Every European A/B testing tool reviewed
Paris, France
PBX Starter from $495 per month (up to 10 experiments, 50,000 tested visitors per month); Enterprise with unlimited experiments and traffic on request
30-day free trial of PBX Starter, up to 3 experiments, no card required
Best for: Teams that need web testing, server-side testing and feature flags from one European vendor
Kameleoon is the only tool in this category that does not make you choose between the marketing half and the engineering half of experimentation. Web experiments with a visual editor, server-side experiments and feature management are sold as one platform, which is the shape Optimizely has and almost nothing European does. For an organisation that would otherwise buy a testing tool and a flag tool and reconcile two sets of numbers, that is the whole argument.
The company is Kameleoon SAS, registered at 12 rue de la Chaussée d'Antin in the 9th arrondissement of Paris under RCS Aix-en-Provence 507 754 570, with offices in Offenburg, London, New York and Ontario.
The privacy policy states that personal data is stored on servers located within the European Union, and the platform runs on dedicated servers rather than public cloud. Kameleoon states ISO 27001 and SOC 2 certification and GDPR, CCPA and HIPAA compliance; among the other tools here only ABsmartly states the same ISO and SOC pair.
Pricing is the honest weak point alongside the detail. PBX Starter is $495 a month for up to ten experiments and 50,000 tested visitors, with a 30-day trial capped at three experiments; everything above that is Enterprise and quoted. And while EU storage is stated, the data centre operator is not named anywhere public, so a procurement team that needs the specific sub-processor will have to ask for it under NDA.
What Kameleoon does well
- Web, server-side and feature experiments in one platform, which only ABsmartly approaches among the European tools here
- ISO 27001 and SOC 2, the strongest stated audit position among the client-side tools here
- French company under EU jurisdiction, with personal data stored on EU servers
- A published entry price of $495 a month rather than a sales call
- 30-day free trial with no card required
Where Kameleoon falls short
- The data centre operator behind "servers within the EU" is not named publicly
- $495 a month is the highest published starting price in this category
- Everything past 50,000 tested visitors a month is a quote
- Not open source, and there is no self-hosted edition
Standout feature. It replaces both halves of Optimizely — Web Experimentation and Feature Experimentation — under one contract and one set of numbers, which only ABsmartly approaches among the European vendors here.
Delhi, India (Wingify); Wingify lists a Paris office
Custom quote; no public AB Tasty price list (abtasty.com now redirects to wingify.com, whose plans page covers the Wingify products)
Not stated for AB Tasty since the move to wingify.com; Wingify offers a free trial account of its own platform
Best for: Large sites that want experimentation and personalisation from a long-established vendor, now part of Wingify
AB Tasty was the biggest European name in this category and still sells the widest surface: A/B/n and multivariate testing, a visual editor, goal tracking and real-time reporting as standard, with personalisation and recommendation modules on top.
Since January 2026 it has been part of Wingify, the company formed when AB Tasty and VWO joined forces: nearly 800 staff, more than 4,000 customers and offices from Paris and Cologne to Delhi, New York and Sydney. Vendor continuity is not the question any more; jurisdiction is.
abtasty.com now redirects to wingify.com, and the Wingify imprint names Wingify Software Pvt. Ltd. in Delhi, India, with VWO co-founder Sparsh Gupta as CEO and EU and UK GDPR representatives appointed under Article 27.
AB Tasty's own privacy policy, which kept visitor personal data inside the EU, no longer has a page of its own. Wingify says it runs data centres in the US, the EU and India, and its privacy policy stores customer account data centrally on Google Cloud in North Virginia. The Paris co-founders, Alix de Sagazan and Rémi Aubert, stay on as executives, but the company named on the site is no longer French.
Pricing was never public and still is not: no AB Tasty price list appears on wingify.com, and Wingify says existing client contracts, pricing, service levels and support continue unchanged after the merger. Wingify offers a free trial account of its own platform; whether that covers the AB Tasty product is not stated. For a buyer who chose AB Tasty because it was French, the honest position is that the product is still here but that reason is not.
What AB Tasty does well
- The broadest feature surface of any European tool in this category
- Wingify states an EU data centre alongside its US and Indian ones
- The Paris co-founders stay on as executives of the merged company
- Existing contracts, pricing and service levels continue unchanged after the merger
- Part of a group with more than 4,000 customers, so vendor continuity is not a question
Where AB Tasty falls short
- Now part of Wingify, whose imprint names an Indian company, Wingify Software Pvt. Ltd.
- No public pricing at all
- Wingify keeps customer account data on Google Cloud in North Virginia, United States
- No security certification is stated on the public pages checked
- Not open source, with no self-hosted option
Standout feature. It still has the widest feature surface of the vendors that started out in Europe, but since the 2026 merger with VWO it is sold by Wingify, so its European case now rests on an EU data centre option rather than on its ownership.
Grünwald, near Munich, Germany
Founded 2019
Growth €199 and Pro €249 per month billed annually (€249 and €349 billed monthly); Enterprise from €799 per month billed annually. Unlimited traffic on every plan; unlimited team members from Pro
15 days free, no card required
Best for: Teams that want a German-hosted testing tool with a price on the website and unlimited traffic
Varify.io is the clearest answer in this category to the question this site exists to ask.
Varify Software GmbH is registered in Grünwald near Munich under HRB 289569, the product is hosted in Frankfurt on AWS and Cloudflare, and the site says "Made & Hosted in Germany" rather than the vaguer "EU hosting" everyone else offers. The company was founded in 2019 by people with more than ten years in CRO who started out as an A/B testing consultancy, which shows in what they chose to leave out.
The pricing model is genuinely unusual: Growth at €199 and Pro at €249 per month billed annually (€249 and €349 monthly), Enterprise from €799, with unlimited traffic on every tier and unlimited team members from Pro. Nobody else here prices on features rather than volume, and for a high-traffic site it changes the arithmetic entirely — a million sessions costs the same as ten thousand. The 15-day free trial needs no card.
The deliberate omissions matter more than the features. Varify leans on the analytics you already run; results are read in GA4, BigQuery, Matomo, Adobe Analytics, Snowplow and other connected tools, which removes arguments about whose numbers are right.
Without one of those, experiments are measured with Varify Tracking, which Varify sets up with you. Server-side testing is Enterprise-only and there are no feature flags, so for most buyers it replaces Optimizely Web and nothing else. Bayesian statistics, outlier smoothing, API access and predefined user roles start on Pro.
What Varify.io does well
- Hosted in Frankfurt, stated outright rather than implied — the most specific claim here
- Published prices from €199 a month with no sales call
- Unlimited traffic on every plan, and unlimited team members from Pro
- Results read in GA4, BigQuery, Matomo or Adobe Analytics rather than a proprietary dashboard
- 15-day free trial, no card required
Where Varify.io falls short
- Server-side testing only on Enterprise, and no feature flags at all
- Built around your existing analytics; without GA4 or similar, measurement runs through Varify Tracking set up with the vendor
- Bayesian statistics, API access and role-based access need the €249 Pro tier
- The Frankfurt hosting runs on AWS and Cloudflare, both US providers
- No security certification is stated, and no free tier below the trial
Standout feature. It charges by capability rather than by traffic, so a site with a million monthly sessions pays the same €199 as a site with ten thousand.
Egham, Surrey, United Kingdom
Founded 2000
Free for sites under 10,000 sessions a month with no feature limits; The Works (managed), DIY (self-service licence) and Hybrid plans all priced on request, scaled on annual sessions
30-day free trial, plus a permanent free tier under 10,000 sessions a month
Best for: Small and mid-sized sites that want a full CRO platform without a contract
Webtrends Optimize has the most useful free tier in this category by a distance: free with no feature limits for any site under 10,000 sessions a month. Not a trial, not a cut-down edition — the full platform, which includes A/B and multivariate testing, server-side testing, personalisation, product recommendations, social proof messaging and surveys. For a site below that threshold, where a test would take months to reach significance anyway, that is exactly the right offer.
The vendor is Accelerate Group Limited, trading as Webtrends Optimize, at Lawrence House, 45 High Street, Egham, Surrey. The testing technology dates back to 2000 and Accelerate Group acquired it in August 2018, so the product is older than the company that runs it. The privacy policy states that all data is stored in Amsterdam, with data collection centres also in Dublin and Australia, and the company is a certified B Corp.
Two things to weigh. The UK sits outside the EEA under an adequacy decision rather than inside the single market, which for some European buyers is a material difference and for others is not; the data itself is in the Netherlands regardless.
And above the free threshold there are no published prices at all — The Works, DIY and Hybrid all read "pricing on request", scaled on annual sessions, so the moment you outgrow the free tier you are in a sales process.
What Webtrends Optimize does well
- Free below 10,000 sessions a month with no feature restrictions
- Full-stack: client-side, server-side, personalisation, recommendations and surveys
- All data stored in Amsterdam, stated in the privacy policy
- Certified B Corp, with a named UK registered address
- 30-day free trial above the free tier
Where Webtrends Optimize falls short
- UK jurisdiction: outside the EEA, under an adequacy decision
- No published prices on any paid tier — all three read "pricing on request"
- Data collection centres in Australia sit outside the EEA
- No security certification stated; B Corp is a governance certification
- Not open source, with no self-hosted option
Standout feature. Below 10,000 sessions a month you get the entire platform for nothing, in a category where the US incumbents start in the tens of thousands per year.
Bucharest, Romania
Founded 2013
Explore free for up to 50,000 tested users a month with the full platform and unlimited tests; paid tiers by traffic band from $350 a month ($2,940 a year) for 100,000 tested users to $2,690 a month for 1 million, over 2 million on request; 30 to 35% off on annual billing
Free plan, no card required
Best for: Ecommerce teams that want testing, surveys and overlays under one login
Omniconvert was built in 2013 by four people in the corner of a Bucharest advertising agency, on the premise that A/B testing, on-site surveys and overlays belong in one product rather than three. That is still the shape of Omniconvert Explore, and it is the reason to choose it: the survey that tells you why visitors abandon and the test that fixes it live in the same tool, with the same segments applied to both.
The entity is Omniconvert SRL at Str. Vasile Stroescu 14, District 2, Bucharest, registered J40/3841/2013 with VAT ID RO 31411197.
The free plan is unusually serious — the full platform, unlimited tests, for up to 50,000 tested users a month with no card required — and paid tiers step up by traffic band from $350 a month for 100,000 tested users to $2,690 a month for one million, with 30 to 35% off on annual billing and a quote above two million.
Explore also covers server-side experiments and native iOS and Android app testing, and offers more than 40 segmentation options.
The gap is transparency about infrastructure. The terms say only that customer data is "stored within the secured Omniconvert infrastructure" — no country, no region, no cloud provider, no sub-processor list on the pages checked.
The company is unambiguously Romanian and therefore under EU jurisdiction, but where the data physically sits is a question you will have to ask in writing. Prices, at least, are printed: the pricing page shows a figure for every band up to one million tested users.
What Omniconvert does well
- Free for up to 50,000 tested users a month with the full platform and unlimited tests
- A/B testing, on-site surveys and overlays in one product with shared segments
- Romanian company with a named Bucharest address and registration number, inside the EU
- Server-side experiments and native mobile app testing included
- More than 40 segmentation options, including geo, device and behavioural triggers
Where Omniconvert falls short
- No hosting location published at all — no country, region or cloud provider named
- Above one million tested users a month the price is a quote
- No security certification stated on the pages checked
- Built around ecommerce, so content and SaaS teams use less of it
- Not open source, with no self-hosted option
Standout feature. The free plan covers 50,000 tested users a month with no feature gate, which is the point at which most small ecommerce sites can run a real test rather than a trial.
Oslo, Norway
Founded 2019
Open Source free and self-hosted with no seat limit (1 project, 2 environments, 5,000 flags per instance); Pay-as-you-go $75 per seat per month (five-seat minimum when self-hosted; 53 million API requests a month included on Cloud, then $5 per million); Enterprise on request
14-day free trial, no card required
Best for: Engineering teams that want experimentation they can run on their own infrastructure
Unleash is what you buy when the answer to "where is our data" has to be "on our servers". Bricks Software AS in Oslo publishes an open-source edition that is free, self-hosted and has no limit on seats, so a hundred engineers cost the same as one. Gradual rollouts, variants, environments and a documented API come with it, and the experiment is a consequence of the rollout rather than a separate product.
The hosted product is Pay-as-you-go at $75 per seat per month (with a five-seat minimum for self-hosted use), or a quoted Enterprise contract, both with a 14-day trial and no card required.
Both paid tiers include a choice of EU or US data residency, which is a rarer commitment than it sounds in a category where most vendors say "EU" and stop. Both also come with SOC 2 Type II, and the security page names Amazon Web Services as the host. Enterprise adds a hosted private instance and multi-region edge.
The limits are real and worth reading before committing. The open-source edition is capped at one project, two environments and 5,000 flags per instance, and leaves out single sign-on, SCIM provisioning, granular access control, change approvals and support SLAs — the exact list a large organisation needs, which is how the licence makes its money.
Norway is in the EEA but not the EU, and there is a US subsidiary, Bricks Software Inc., in the corporate structure. And this is not a marketing tool: there is no visual editor, so changing a headline still takes a deploy.
What Unleash does well
- Open source and free to self-host with no seat limit
- EU or US data residency as a choice on both paid tiers
- Norwegian parent company, with the source available so the deployment can be entirely yours
- Gradual rollouts, variants and environments built for safe releases, not just tests
- 14-day free trial on the hosted product, no card required
Where Unleash falls short
- No visual editor, so a marketer cannot run a test without engineering
- The open-source edition caps at one project, two environments and 5,000 flags
- SSO, SCIM, granular access control and change approvals are paid-only
- $75 per seat is the only per-person price in this category
- Norway is in the EEA but outside the EU, and there is a US subsidiary in the group
Standout feature. It is one of two tools here you can run with no vendor in the chain at all, at any team size, which removes the processor question rather than moving it to a friendlier country.
Helsinki, Finland
Founded 2008
On request; no public price list and no pricing page on the site
Best for: Finnish and Nordic sites that want personalisation with optimisation built in
Frosmo has been doing this longer than most of the category: founded in Helsinki in 2008, at Lautatarhankatu 6, as Frosmo Technologies Oy. The product is a personalisation platform first and a testing tool second — it captures visitor data, acts on it automatically, and runs A/B testing as part of the optimisation loop rather than as a separate workflow you open on Tuesdays.
The residency picture is more specific than most here because the data processing annex names its sub-processors outright: Hetzner Online AG, Hetzner Finland Oy and Amazon Web Services, Inc.
The privacy policy states that personal data of EU/EEA users is not transferred outside the EU/EEA, though it also notes that third-party analytics used on Frosmo's own website may process data on US servers. Naming Hetzner Finland alongside Hetzner Germany is the kind of detail that makes a Nordic procurement conversation short.
What Frosmo does not have is a price. There is no pricing page on the site and no published figure anywhere, which in practice means an enterprise sales cycle and an annual contract.
There is no free tier and no self-service trial either. The automated, AI-driven approach also suits a merchandising team more than an experimentation team: if you want to run a carefully designed hypothesis test with a pre-registered primary metric, this is not the tool built for that ritual.
What Frosmo does well
- Finnish company, founded 2008, with a named Helsinki address
- Sub-processors named outright: Hetzner Online, Hetzner Finland and AWS
- Privacy policy states EU/EEA personal data is not transferred outside the EU/EEA
- Automated, AI-driven optimisation rather than manual test management
- Personalisation and testing in one platform, so segments are shared
Where Frosmo falls short
- Amazon Web Services is a named sub-processor, so a US provider sits in the chain
- No published pricing, no pricing page, and no free tier or self-service trial
- Personalisation-first, so disciplined hypothesis testing is not the primary workflow
- No security certification stated on the pages checked
- Not open source, with no self-hosted option
Standout feature. It names its infrastructure sub-processors, Hetzner Finland among them, in the data processing annex itself, which is the document a Nordic procurement team will ask for first.
London, United Kingdom
Free (50,000 requests a month, one team member, unlimited flags, environments, identities and segments); Start-Up $40 per month billed annually or $45 monthly, which is where A/B testing begins; Scale-Up $250 annually or $300 monthly with five team members included, up to 20 at $50 to $60 per extra member; Enterprise on request. Overage from $50 per extra million API calls
Free tier, plus a 14-day free trial on the Start-Up and Scale-Up plans
Best for: Developers who want open-source feature flags with A/B testing attached
Flagsmith is the cheapest realistic entry point into experimentation in this category. Bullet Train Limited, company number 12353266, at 66 Paul Street in London, publishes the platform under BSD-3-Clause — a permissive licence rather than a copyleft one, so you can run it, modify it and keep the changes. The free tier covers 50,000 requests a month with one team member and unlimited flags, environments, identities and segments; A/B testing arrives on the $40 Start-Up plan.
The pricing ladder is legible in a way most of this category is not: $40 a month annually or $45 monthly for a million requests and three team members, $250 or $300 for five million requests and five team members, extendable to twenty at $50 to $60 per extra member, then Enterprise.
Overage runs from $50 per additional million API calls and falls with volume. Self-hosting is documented for Docker, Kubernetes with Helm, OpenShift, AWS and Google Cloud, and private cloud can be deployed in a region you pick.
Two caveats. The SaaS hosting story is the vaguest in this category: the pricing page says the cloud is "optimised over eight regions across the world" and does not name any of them, while the privacy policy names AWS as its third-party processor without a region, which for a European buyer is not an answer — the practical response is private cloud or self-hosting, both supported.
And the UK sits outside the EEA under an adequacy decision, so a buyer who has made intra-EEA processing a hard requirement will land on Unleash or ConfigCat instead.
What Flagsmith does well
- Open source under BSD-3-Clause, a permissive licence with no copyleft obligation
- Free tier with 50,000 requests, unlimited flags, environments, identities and segments
- A/B testing from $40 a month, the lowest published price in this category
- Self-host on Docker, Kubernetes, OpenShift, AWS or Google Cloud, or private cloud in your chosen region
- Published price ladder including overage rates, with no sales call needed
Where Flagsmith falls short
- The SaaS cloud regions are not named anywhere public
- UK jurisdiction: outside the EEA, under an adequacy decision
- No visual editor, so this replaces Optimizely Feature Experimentation and not Optimizely Web
- The free tier allows a single team member
- No security certification stated on the pages checked
Standout feature. A permissive BSD-3 licence means you can fork it and keep your changes private, which no other tool in this category permits.
Budapest, Hungary
Forever Free $0 (10 flags, 2 environments, 2 products, 5 million config downloads a month); Pro $110; Smart $325; Enterprise $900; Dedicated $4,500 per month. Billable in USD, EUR, GBP or AUD, up to 10% off annually
Forever Free plan, no card required
Best for: Teams that want an audited feature flag service with an EU-only serving option
ConfigCat sells a narrow product well. Feature flags with A/B/n testing through percentage rollouts, user targeting and segmentation, delivered from ConfigCat Kft. at Tátra utca 5/A in Budapest under company registry 01-09-352162. It holds ISO/IEC 27001:2022, publishes a Trust Center with a named sub-processor list, runs a bug bounty and commits to SLAs from 99% to 99.99% depending on tier — a level of documentation most vendors this size do not bother with.
The price ladder is published in full and in four currencies: Forever Free with 10 flags and 5 million config downloads a month, Pro at $110, Smart at $325 with unlimited flags and seats, Enterprise at $900 and a Dedicated private-cloud tier at $4,500 a month. Architecturally it is careful about data: flag values and targeting rules are what ConfigCat stores, and evaluation happens client-side, so your users' attributes need never leave your system.
The honest caveat is infrastructure, and it is the reason ConfigCat sits here rather than higher. The published sub-processor list names Akamai Technologies International AG in Switzerland alongside Amazon Web Services, Cloudflare and DigitalOcean, all United States companies.
The company is Hungarian and therefore under EU jurisdiction, and an "EU Only" data governance setting keeps served config JSONs on EU CDN nodes, but the infrastructure underneath is American. ConfigCat is also unambiguously an engineering tool: no visual editor, and the experimentation reporting leans on integrations with analytics products rather than a dashboard of its own.
What ConfigCat does well
- ISO/IEC 27001:2022 certified, with a Trust Center and a published sub-processor list
- Full price ladder published in USD, EUR, GBP and AUD, from a Forever Free plan
- "EU Only" data governance setting keeps served config JSONs on EU CDN nodes
- Client-side evaluation, so end-user attributes need not reach ConfigCat at all
- Hungarian company under EU jurisdiction, with a Dedicated private-cloud tier available
Where ConfigCat falls short
- Sub-processors are AWS, Cloudflare and DigitalOcean — US infrastructure under a European company
- No visual editor, so this replaces Optimizely Feature Experimentation and not Optimizely Web
- The free plan caps at 10 flags, 2 environments and 2 products
- Experiment reporting depends on integrations rather than a built-in analysis view
- The service itself is not open source, only the SDKs
Standout feature. The "EU Only" data governance setting is the rare case of a vendor building the residency question into the product as a switch rather than answering it in a PDF.
Stockholm, Sweden
On request; no public price list and no pricing page on the site
Best for: Nordic marketing teams that want testing inside the same tool as their campaigns
Symplify Technologies AB sits at Drottninggatan 55 in Stockholm, with offices in Canada, Denmark, Hong Kong and Malta, and describes twenty years of web experience behind the platform. The conversion suite is one part of a larger engagement ecosystem: A/B testing, heatmaps, visitor recordings, personalisation, popups, web push and surveys, all delivered through a single script, sitting alongside the CRM and marketing automation half of the product.
That bundling is the argument. If your campaign emails, your on-site popups and your A/B tests all live in the same platform, the segment you built for one is available to the others and there is no integration to maintain between them. For a gaming, fintech or retail marketing team already looking at a Nordic engagement platform, adding conversion testing is a line item rather than a separate procurement.
The documentation is the weak spot. The privacy policy states that Symplify only works with partners that process personal data within the EU/EEA, or that meet the same level of security the EU/EEA requires, and that its systems are adapted to Swedish and EU privacy law, but names no data centre, no country and no cloud provider.
There is no pricing page and no published figure. No security certification is stated. And a team that wants a dedicated experimentation platform will find the testing half thinner than Kameleoon or AB Tasty, because it is not the centre of the product.
What Symplify does well
- Swedish company at a named Stockholm address, under EU jurisdiction
- A/B testing, heatmaps, session recordings, popups and surveys through one script
- Testing shares segments with the CRM and marketing automation half of the platform
- Privacy policy commits to partners processing personal data inside the EU/EEA or to an equivalent standard
- Twenty years of web experience behind the product, with offices across four countries
Where Symplify falls short
- No data centre, country or cloud provider named anywhere public
- No pricing page and no published prices at all
- Testing is one module of a wider suite, so it is shallower than a dedicated platform
- No security certification stated on the pages checked
- Not open source, with no self-hosted option
Standout feature. The test and the campaign that follows it run on the same segments in the same tool, which removes the integration every other pairing in this category needs.
Barcelona, Spain
Starter free (500 tested page views a month, one site); Basic 5,000 views and one site; Professional 50,000 views and five sites; Enterprise 200,000 views and unlimited sites — the paid prices are not printed on the pricing page and appear only at checkout, monthly or yearly with 20% off annually
Free Starter plan through wordpress.org, plus a 30-day money-back guarantee on paid plans
Best for: WordPress sites that want to test posts, pages and templates from inside the admin
Nelio A/B Testing is the only tool in this category that understands what a WordPress post is. Built by Nelio Software, S.L. at C/ Pomaret 83 in Barcelona, NIF ESB66034794, it runs inside the WordPress admin and tests the objects WordPress actually has — posts, pages, templates, themes, widgets, menus — rather than asking you to point a visual editor at a DOM element and hope the selector survives the next theme update.
The free Starter plan comes through wordpress.org and covers 500 tested page views a month on one site, which is enough to learn the tool rather than to run a business on it.
Paid tiers step up on tested page views: Basic at 5,000 views and one site, Professional at 50,000 views and five sites, Enterprise at 200,000 views and unlimited sites, monthly or yearly with 20% off annually, and a 30-day money-back guarantee. The company also makes Nelio Content, Session Recordings, Popups and Forms, so the plugins share an account.
Two limits define it. The paid prices are not printed on the pricing page and appear only at checkout, which is an odd choice for a self-service plugin and makes comparison harder than it should be.
The residency question does have an answer, though it sits in a 50-page PDF: the data processing agreement names Amazon Web Services, with data centres in the EU (primarily Ireland and Germany), as the hosting sub-processor. And the reach is narrow: Nelio also sells a Shopify app, but any part of the funnel that lives on neither platform is invisible to it.
What Nelio A/B Testing does well
- Tests WordPress objects natively — posts, pages, templates, themes, widgets and menus
- Runs inside the WordPress admin, so no separate platform to learn
- Free plan through wordpress.org covering 500 tested page views a month
- Spanish company with a named Barcelona address and NIF, inside the EU
- 30-day money-back guarantee on paid plans
Where Nelio A/B Testing falls short
- WordPress and Shopify only, so any other part of the funnel is out of reach
- Paid prices are not shown on the pricing page, only at checkout
- Hosting runs on Amazon Web Services, a US provider, albeit in EU data centres
- The free plan's 500 tested page views a month will not reach significance on anything
- No security certification stated, and no server-side testing or feature flags
Standout feature. It tests WordPress content types directly instead of CSS selectors, so a theme update does not silently break every running experiment.
Amsterdam, Netherlands
No public price list; the pricing page redirects straight to a demo request, and plans are sold as yearly subscriptions quoted per customer
No free trial; a paid 30-day Proof of Value ahead of a yearly subscription
Best for: Product and engineering teams that want Booking.com-grade experimentation
ABsmartly is the closest thing to a second Kameleoon in this category: a dedicated, full-stack experimentation platform rather than a bundle bolted onto marketing software, built specifically to compete with Optimizely, Statsig and LaunchDarkly on engineering-grade experimentation.
It was founded by Jonas Alves, who spent seven years architecting the experimentation platform behind Booking.com, scaling it past 1,000 concurrent experiments — a pedigree not many European vendors here can claim. Its headline feature is Group Sequential Testing, which lets a team check results daily without inflating false positives, reaching significance 20% to 80% faster than a fixed-horizon test.
The company is ABsmartly B.V., registered at Keizersgracht 520 H in Amsterdam.
Unlike most of this category, ABsmartly states its security posture rather than leaving it implicit: its information security management system is certified against ISO/IEC 27001:2013, and the platform is also SOC 2 Type II, GDPR and HIPAA compliant, with independent penetration testing stated. That combination — ISO 27001 plus SOC 2 — is matched only by Kameleoon among the tools in this directory, which states HIPAA compliance as well.
The gap is transparency about infrastructure and price. ABsmartly's own sub-processor list names Amazon Web Services as its cloud host with no EU region specified, so "Dutch company" does not automatically mean "EU-hosted data" the way it does for Varify.io.
There is no public pricing page — it redirects straight to a demo request — and no free trial, only a paid 30-day Proof of Value ahead of a yearly subscription. On-premises deployment is offered for teams that want to sidestep the hosting question entirely, at the cost of running it themselves.
What ABsmartly does well
- ISO/IEC 27001:2013 and SOC 2 Type II, matched only by Kameleoon in this category
- Group Sequential Testing reaches significance 20-80% faster than fixed-horizon tests
- Built by the team that scaled Booking.com to 1,000+ concurrent experiments
- On-premises deployment available for teams that want the data entirely in-house
- States GDPR and HIPAA compliance, with independent penetration testing
Where ABsmartly falls short
- No public pricing at all; the pricing page redirects straight to a demo request
- No free trial; the 30-day Proof of Value is paid
- Named cloud sub-processor (AWS) is US-based with no EU region stated
- Not open source; marketers get a visual editor only through the LaunchPad browser extension
Standout feature. Its ISO 27001 and SOC 2 combination, paired with Group Sequential Testing, targets the same engineering buyer as Optimizely Full Stack.
London, United Kingdom
Founded 2008
Solo £45 / €49 / $59 per month for up to 20,000 visitors and 3 projects (£35 / €39 / $49 billed annually); Team from £175 / €199 / $249 per month for up to 100,000 monthly visitors, rising with traffic to £759 / €899 / $999 for up to 2,000,000 visitors
14-day free trial, no credit card required
Best for: Small teams that want a published price and psychology-based test ideas
Convertize's pitch is unusual for this category: rather than assuming you already know what to test, it ships more than 150 documented A/B testing ideas grounded in consumer psychology research, so a marketer without a hypothesis can start from a library instead of a blank page.
Autopilot mode, a multi-armed bandit, reallocates traffic to the better-performing variant automatically, and a Hybrid statistical engine is meant to shorten how long a test needs to run before it is trustworthy. It sits alongside Kameleoon, AB Tasty and Varify.io as a straightforward client-side testing tool with a visual SmartEditor, not a feature-flag system.
Convertize Ltd has been registered in the United Kingdom since 10 September 2008, company number 06694068, currently listed at 12 Hammersmith Grove in London.
Pricing is published rather than quoted: the Solo plan is £45 / €49 / $59 a month for up to 20,000 visitors and three projects, and the Team plan starts at £175 / €199 / $249 a month for up to 100,000 monthly visitors, rising with traffic to £759 / €899 / $999 for up to 2,000,000 visitors, with two months free on annual billing. A 14-day free trial needs no card.
Two gaps are worth flagging. The United Kingdom sits outside the EEA under an adequacy decision rather than inside it, which for some European buyers is a material difference. And while the privacy policy places its databases and servers within the European Union, held by Convertize or by equivalent third-party providers, it names neither a provider nor a country.
What Convertize does well
- 150+ built-in A/B testing ideas grounded in consumer psychology research
- Autopilot multi-armed bandit traffic allocation included
- Published pricing from £45 / €49 / $59 a month for the Solo plan
- 14-day free trial, no credit card required
- UK company registered since 2008, a stable, long-lived entity
Where Convertize falls short
- United Kingdom jurisdiction: outside the EEA, under an adequacy decision
- EU hosting is stated, but no provider or country is named
- The Solo plan caps at 20,000 visitors and three projects
- No security certification stated
- Not open source, with no self-hosted option
Standout feature. Its library of 150+ documented, psychology-based testing ideas gives a team without a hypothesis somewhere to start.
Budapest, Hungary
Founded 2014
Free $0 (10,000 pageviews/month, 1 domain, all features); Essential $19/month ($228/year); Growth $69/month ($828/year); Premium $179/month ($2,148/year); Master custom, on request
Free plan available indefinitely rather than a time-limited trial
Best for: Ecommerce brands that want popups, personalization and testing for free
OptiMonk sits in the same bundled-ecommerce bracket as Omniconvert: A/B testing here is one feature inside a popup, on-site messaging and personalization builder rather than a standalone product, and it is included on every tier — including the free one. AI-generated campaign copy and variants, unlimited campaigns and a key account manager are listed as included from the Free plan upward, which is a more generous free tier than anything else in this category besides Webtrends Optimize.
The company is OptiMonk International Zrt, based in Budapest and founded in 2014.
Pricing is fully published and genuinely tiered by traffic: Free at $0 for 10,000 pageviews a month and one domain, Essential from $19, Growth from $69 and Premium from $179, each rising with pageview volume, plus a custom Master tier on request. Hosting runs on DigitalOcean, and the privacy policy specifies that OptiMonk uses only DigitalOcean's EU data centres, in Frankfurt — a more specific claim than most of this category makes, even though DigitalOcean itself is a US company.
No security certification is stated on the pages checked, and OptiMonk is built for ecommerce conversion — popups, cart-abandonment messaging, lead capture — rather than for a SaaS or content team running a disciplined, pre-registered hypothesis test. A team that wants dedicated experimentation infrastructure rather than a popup builder with testing attached should look at Kameleoon or ABsmartly instead.
What OptiMonk does well
- Genuine free tier at $0 with unlimited campaigns and all features
- Hosted on DigitalOcean's EU data centres in Frankfurt, stated outright
- Full price list published, from $19 a month
- Hungarian company, founded 2014, under EU jurisdiction
- AI-generated campaign copy and popup variants included
Where OptiMonk falls short
- No security certification stated on the pages checked
- Built for ecommerce popups and on-site messaging, not general-purpose A/B testing
- DigitalOcean, the named hosting sub-processor, is a US company
- Pricing is tied to pageviews rather than tested visitors, a different unit from most of this category
Standout feature. Its Free plan includes every feature, including A/B testing, up to 10,000 pageviews a month — a rarer offer than the trials everyone else here runs.
Gliwice, Poland
Founded 2011
Build $24/month, Optimize $119/month (where server-side A/B testing starts), Scale from $229/month, Enterprise from $1,199/month; annual billing includes two free months
14-day free trial on every plan
Best for: Marketers who want landing pages and A/B testing in one tool
Landingi answers a different question than most of this category: not "how do I test a page I already built" but "how do I build and test the page in the same tool".
Landing pages, AI-assisted copy through its Lunar generator, forms and 400+ templates come first; Server-Side A/B Testing is bundled in from the Optimize plan upward, alongside EventTracker micro-conversion tracking and Solis AI insights. For a marketing team whose landing pages and their tests live in different platforms today, collapsing them into one bill and one login is the entire pitch.
The company is Landingi Sp. z o.o., registered at Dworcowa 25 in Gliwice under KRS number 0000449404, founded in 2011 and headquartered in Europe with a second office in Dallas, Texas. Its Terms of Use name the Polish entity, not the US one, as the owner of the service and the contracting party, though its privacy policy lists Landingi Inc. as a joint controller alongside it for data-processing purposes.
Pricing is fully published: Build at $24 a month, Optimize (where A/B testing starts) at $119, Scale from $229 and Enterprise from $1,199, with two free months on annual billing and a 14-day trial on every tier. Where the servers sit is published on the infrastructure page rather than in the privacy policy: customer data is stored and processed on AWS in the European Union, while published pages go out through a global delivery network in more than 20 locations.
What Landingi does well
- Landing pages and A/B testing in one platform, one login, one bill
- Full price list published, from $24 a month
- 14-day free trial on every plan
- Polish company (Gliwice), the named Service Provider in its own Terms of Use
- AI-generated pages and copy through the Lunar builder
Where Landingi falls short
- A/B testing is not on the entry-level Build plan; it starts at $119/month on Optimize
- Hosting runs on AWS, a US provider, albeit in the EU, with pages served from a global network
- A US entity (Landingi Inc.) is joint controller for data processing
- No security certification stated
- Built around landing pages rather than full-site testing
Standout feature. The A/B test and the landing page it runs on are built in the same editor, so nothing has to sync between two tools.
Munich, Germany
On request; no public price list and no pricing page on the site
Best for: German and DACH retailers that want personalization and testing together
trbo sits in the same personalization-first bracket as Frosmo: A/B, multivariate and multi-armed bandit testing exist inside trbo, but they sit alongside product recommendations, on-site messaging and a chatbot rather than standing alone as the product. trbo GmbH is based in Munich and captures more than 50 visitor characteristics per session to drive its personalization, testing and recommendation modules from one account.
More than 300 companies use it, including Deutsche Telekom and the diaper brand LILLYDOO, whose own case study credits trbo's A/B testing for validating a product-recommendation change before it was rolled out permanently.
The controlling entity is trbo GmbH, registered at Leopoldstraße 41 in Munich under HRB 205778 at the Munich district court, with VAT ID DE289648172. Like Unleash and Flagsmith, trbo is not a single-country operation: a sister company, trbo Inc., operates out of Miami, Florida, though the GDPR-facing data controller named in the privacy policy is the German GmbH.
What trbo does not publish is everything a procurement checklist wants filled in. There is no pricing page and no figure anywhere on the site, so budgeting means a sales conversation.
No hosting location, cloud provider or sub-processor list for the platform was found on the pages checked (the privacy policy only places the servers for trbo's own website in Germany and Belgium), which for a personalization tool that reads over 50 characteristics per visitor is a bigger gap than it would be for a simple test runner. No security certification is stated either.
What trbo does well
- A/B, multivariate and multi-armed bandit testing built into one personalization platform
- German company (Munich), with over 50 visitor characteristics captured for targeting
- Trusted by 300+ companies including Deutsche Telekom
- Product recommendations, on-site messaging and a chatbot bundled with testing
- No-code campaign builder for non-technical marketing teams
Where trbo falls short
- No pricing page and no published figures anywhere on the site
- No hosting location, cloud provider or sub-processor list published
- No security certification stated on the pages checked
- A US sister company (trbo Inc., Miami) sits in the same corporate group
- Testing is one module of a personalization suite, not a dedicated platform
Standout feature. It captures more than 50 visitor characteristics per session and turns every one of them into a testing or targeting variable.
Helsinki, Finland
Founded 2013
On request; no public price list, quoted after a demo
Best for: Ecommerce brands that want AI merchandising with testing built in
Nosto is the most personalization-first tool in this category, closer in spirit to Frosmo or trbo than to a dedicated testing platform: A/B Testing & Optimization is one named module inside a Commerce Experience Platform that also covers personalized search, category merchandising, product recommendations, post-purchase upsell and shoppable UGC. For a retailer that already wants AI-driven merchandising, adding the A/B testing module tests the merchandising changes in the same account rather than exporting data to a separate tool.
The company is Nosto Solutions Oy, registered at Bulevardi 21 in Helsinki and founded in 2013 by Jani Luostarinen, Antti Pöyhönen and Juha Valvanne. Nosto also operates local entities across Europe and beyond — Nosto Solutions Ltd (Finland), Nosto Solutions UK Ltd, Nosto Solutions GmbH (Germany), Nosto Solutions AB (Sweden) and Nosto Solutions SAS (France) all appear as affiliate sub-processors — a wider stated European footprint than most tools in this category.
The infrastructure claim is the weak point. Nosto's published sub-processor list names Amazon Web Services, Inc. for hosting and storage in the United States, and Amazon Web Services Australia Pty Ltd for hosting and storage in Australia — no EU hosting location is named for the data itself, despite the Finnish parent company and its European affiliate network. There is no public pricing; every plan is quoted after a demo, and no security certification is stated on the pages checked.
What Nosto does well
- A/B Testing & Optimization sits alongside AI merchandising, search and personalization in one account
- Finnish company (Helsinki), founded 2013, with affiliate entities across Germany, Sweden, France and the UK
- Named founders and a transparent corporate structure
- Suited to retailers who want testing and merchandising to share the same data
Where Nosto falls short
- Primary hosting sub-processors are United States and Australian AWS entities, not European ones
- No public pricing; every plan is quoted after a demo
- No security certification stated on the pages checked
- A/B testing is one module of a much larger platform, not a dedicated tool
- Not open source, with no self-hosted option
Standout feature. Its European affiliate network spans Finland, Germany, Sweden, France and the UK, even though the hosting itself runs on US and Australian AWS.
