Every European diagram software tool reviewed
Northampton, United Kingdom
Free; the site says free forever, no sign-up required, no paywalled enterprise tier
Demo on request
Best for: Anyone who needs Visio-style flowcharts and network or architecture diagrams without a licence fee
draw.io, also served as diagrams.net, is a diagram editor that runs in the browser or as a desktop app and costs nothing. Its home page says it has been available since 2005 and that files created then still open. Real-time collaboration shows shared cursors, and diagrams export to SVG, PNG and PDF. Integrations named on the site include Google Drive, SharePoint, OneDrive, Teams, GitHub, VS Code and Notion.
The terms are an agreement with draw.io Ltd, registered in England and Wales under company number 04051179 with its office in Northampton, and governed by English law. The privacy statement says diagrams are saved on your device or connected storage, while PDF export, collaboration and AI features pass the diagram through provider servers without keeping it. The Confluence and Jira apps come from Seibert Group GmbH under a separate licence.
What draw.io does well
- Free with no sign-up and no paywalled enterprise tier according to the site
- Apache 2.0 source code on GitHub
- Diagrams stay in storage you choose
- Desktop app and many native integrations
- Files from 2005 still open
Where draw.io falls short
- draw.io cannot recover files lost from your storage
- Several functions send the diagram to provider servers (not stored)
- Confluence and Jira apps sit under a separate vendor licence
- Contracting entity is in the UK, not the EU
Standout feature. draw.io is the only tool here that combines a free desktop app, public Apache 2.0 source code and native Microsoft, Google and GitHub integrations.
Tübingen, Germany
Free of charge, including in a commercial environment, under the yEd Software License Agreement
Demo on request
Best for: Network, org and process graphs where automatic layout saves manual arranging
yEd is the free desktop diagram editor of yWorks, the company behind the yFiles diagramming library. The vendor says its layout algorithms arrange large data sets at the press of a button, and the editor imports data from Excel .xls and XML. It draws flowcharts, UML class diagrams, BPMN, family trees and social networks, and exports to PNG, JPG, SVG, PDF and SWF.
The yEd Software License Agreement is between yWorks GmbH and the licensee, governed by German law, with the legal page giving Vor dem Kreuzberg 28 in Tübingen. Use is free, including commercially, but you may not redistribute yEd or run it in an automated process. The browser version, yEd Live, keeps graphs in your browser unless you save to a supported cloud service or use its ChatGPT-based AI features.
What yEd does well
- Free of charge, including commercial use
- Automatic layout algorithms for large diagrams
- Runs on Windows, macOS and Linux
- yEd Live keeps diagrams in the browser
- German vendor with German-law licence
Where yEd falls short
- Not open source, with redistribution limits
- No real-time collaboration described on the pages checked
- Excel import is limited to .xls
- AI features in yEd Live use ChatGPT
Standout feature. yEd turns imported data into an arranged diagram through built-in layout algorithms, which no other tool here offers as its core feature.
Bratislava, Slovakia
Standard edition free for non-commercial use only; 30-day trial of the other editions; paid editions (Premium, Professional, Ultimate, Customized) see website
Demo on request
Best for: Software analysts who want UML, ERD and BPMN diagrams in one installed tool
Software Ideas Modeler is a CASE tool and diagram editor supporting UML, SysML, ERD, BPMN, ArchiMate, flowcharts, user stories and wireframing. The home page gives version 15.55, released on 13 August 2026. It adds macros and tools for code and database integration, and real-time collaboration works through a separately installed Software Ideas Server.
The end-user licence agreement names Dušan Rodina, Šancová 3/A, 811 04 Bratislava, Slovakia as the licensor, so the vendor is an individual rather than a company. The licence lists five editions, Standard, Premium, Professional, Ultimate and Customized, with a 30-day trial. Standard is free for schools, non-profit organisations and home users only, and the pages checked show no prices for the paid editions.
What Software Ideas Modeler does well
- Wide notation coverage: UML, SysML, ERD, BPMN, ArchiMate
- Free Standard edition for non-commercial use
- 30-day trial of the paid editions
- Macros and code and database integration
- Slovak licensor under EU law
Where Software Ideas Modeler falls short
- Prices not shown on the pages checked
- Free edition not allowed for commercial use
- Single-person vendor
- Collaboration needs a separate server install
Standout feature. Software Ideas Modeler puts UML, SysML, ERD, BPMN and ArchiMate into one installed program built and licensed by a single Slovak developer.
Berlin, Germany
Desktop Modeler included in the free self-managed Development tier; Web Modeler, production licences and Camunda SaaS: talk to sales, 30-day free trial of SaaS
Demo on request
Best for: Teams that want BPMN diagrams to execute as processes, not only document them
Camunda Modeler is where business teams and developers draw BPMN processes in the Camunda platform. The vendor says the diagram that business reviews is the exact model that runs in production, and that processes stay portable because they use open BPMN. The Desktop Modeler handles BPMN, DMN decision tables and forms locally, with version 5.52.0 listed on 6 October 2026.
The imprint names Camunda Services GmbH at Zossener Straße 55-58, 10961 Berlin, registered at Amtsgericht Charlottenburg under HRB 113230 B. The terms send customers in the US, Canada and Mexico to Camunda, Inc. in San Francisco under Delaware law. Web Modeler adds collaborative modelling and Git Sync, and Camunda Copilot drafts processes from a description, always subject to approval according to the vendor.
What Camunda Modeler does well
- Free Desktop Modeler in the Development tier
- BPMN, DMN and forms in one place
- Token flow simulation in the Desktop Modeler
- German contracting entity for most regions
- Built on open BPMN
Where Camunda Modeler falls short
- Not a general-purpose diagram editor
- Pricing on request for Web Modeler and production
- Hosting region of Web Modeler not stated
- US, Canada and Mexico customers contract with Camunda, Inc.
Standout feature. Camunda Modeler is the only tool in this category where the drawn diagram is deployed and executed as the running process.
Ivry-sur-Seine, France
Open-source edition free (GPL-3.0); commercial Docaposte offer on request
Demo on request
Best for: Enterprise architects and analysts who need UML, BPMN and ArchiMate in one open-source tool
Modelio is a modelling environment that, according to its site, covers enterprise architecture, process modelling, software development and systems engineering. It combines UML 2, BPMN 2, ArchiMate 3.2, SysML and TOGAF, with Java code generation, XMI import and export and automatic documentation to Office, LibreOffice and web formats. Modelio Reader opens models in a browser.
The open-source edition sits on GitHub under GPL-3.0 and modeliosoft.com now redirects to a Docaposte page. Docaposte describes itself as a subsidiary of Groupe La Poste, registered in Créteil under number 493 376 008. When we checked, modelio.org showed a maintenance notice, and neither the commercial price nor the hosting of the central repository is published.
What Modelio does well
- GPL-3.0 open-source edition
- UML, BPMN, ArchiMate, SysML and TOGAF in one tool
- Java code generation and XMI exchange
- Automatic documentation in Office and web formats
- French group behind the commercial offer
Where Modelio falls short
- Heavier than a drawing tool
- modelio.org was in maintenance when checked
- Prices not published
- ArchiMate delivered as an extension
Standout feature. Modelio is the only tool here that pairs an open-source GPL-3.0 edition with TOGAF and ArchiMate support and a French commercial vendor.
La Chevroliere, France
Paid plans Pro, Team, Business and Enterprise: Pro EUR 10 per member per month or EUR 100 per year, Team EUR 100 and Business EUR 130 per member per year at the smallest size band, cheaper above 50 and 200 members, Enterprise by quote.
Demo on request
Best for: Workshop teams that want a visual workspace hosted in France with published euro prices and a free plan
Draft.io is a collaborative visual workspace operated by Draft SAS, registered in the Nantes trade register under number 848 959 268 with its seat in La Chevroliere. It calls its boards drafts and counts usage in objects, not boards. The free plan has unlimited drafts, participants and guest editors within a 500-object limit and already includes facilitation features and a Jira integration.
The enterprise page names TUI, Le Bon Coin, Enedis, AXA and SNCF as customers and names OVH as the French hosting provider. Draft.io lists ISO 27001, SOC 1 and SOC 2 in connection with the hosting, while the security page names no certificate issued to Draft SAS. Business, at EUR 130 per member per year, is where SAML SSO starts, and it requires 50 members.
What Draft.io does well
- OVH in France is named as the host for every Draft.io plan.
- Unlimited drafts and guests sit inside a free tier capped by objects.
- Per-member prices on Team fall in steps once you pass 200 seats.
- A Jira connection and workshop facilitation tools come without paying.
- A dedicated or on-premise setup exists for Enterprise buyers.
Where Draft.io falls short
- Single sign-on needs the Business tier and at least 50 seats.
- No certificate in the name of Draft SAS appears on its security page.
- Payment, mail and webinar sub-processors on the privacy page are US companies.
- VAT treatment and any paid-plan trial go unmentioned on the price page.
Standout feature. Draft.io names its French host, OVH, on every plan including the free one and still allows unlimited participants.
Halle (Saale), Germany
Founded 2010
Three paid tiers: Starter at EUR 5, Advanced from EUR 10 (12-month term from 10 users) and Corporate & Government from EUR 14 (24-month term from 100 users), per user per month, excluding VAT; single-tenant and on-premises by request.
Demo on request
Best for: Organisations that need ISO-certified German hosting for reviewing visual work with external participants
Conceptboard is a browser-based whiteboard that runs without installation, lets external participants join through a link and adds task management with Kanban structures and timelines. It connects to Microsoft Teams, Google Drive, OneDrive, Dropbox, Webex and Confluence. The company dates its launch to 2010 and reports 6,500 customers and 93 employees, which are vendor figures.
Conceptboard Cloud Service GmbH is registered at Amtsgericht Stendal under HRB 29184 with its address in Halle (Saale). Its security page lists ISO/IEC 27001:2022, 27017:2015 and 27018:2019, with TLS 1.2 in transit and AES-256 at rest. It hosts on IONOS and Amazon Web Services in Frankfurt, and single sign-on and audit logs only come with the Corporate & Government plan.
What Conceptboard does well
- Three ISO/IEC standards (27001, 27017, 27018) are listed on the security page.
- Frankfurt is the stated data location, with IONOS or StackIT as options from Advanced up.
- Three paid tiers carry public per-user prices between EUR 5 and EUR 14.
- A 3-board free plan exists and paid tiers start with a 30-day trial.
- Single-tenant or on-premises operation can be requested.
Where Conceptboard falls short
- Amazon Web Services in Frankfurt is named next to IONOS in the default hosting statement.
- Choosing IONOS or StackIT adds a fee.
- SSO and audit logs require the top tier, 100 users and 24 months.
- The free plan stops at 100 objects per board and 250 MB.
Standout feature. Conceptboard is the only tool here that combines three stated ISO certificates, a German operator and a named Frankfurt hosting location.
Brno, Czech Republic
Free editor; the paid Excalidraw+ is USD 6 per user per month, 14% cheaper billed yearly.
Demo on request
Best for: Engineers who want an MIT-licensed, offline-capable sketching tool with encrypted collaboration
Excalidraw is an open-source whiteboard for hand-drawn style diagrams, published under the MIT licence. The free editor at excalidraw.com supports real-time collaboration with end-to-end encryption, works offline as a PWA, autosaves in the browser and exports to PNG, SVG or an .excalidraw file. Excalidraw+ adds cloud-saved scenes, comments, presentations and PDF and PPTX export.
The Excalidraw+ terms name Excalidraw s.r.o., Prazakova 1008/69, Brno, as the operator, under Czech law. The privacy policy says servers are in the United States, with standard contractual clauses for transfers. Excalidraw+ costs USD 6 per user per month, and a self-hosted instance supports no sharing without the separate collaboration server.
What Excalidraw does well
- The code base is MIT-licensed and public.
- Live sessions in the free editor are end-to-end encrypted.
- It keeps working offline as a PWA with local autosave.
- Excalidraw+ has one price, USD 6 per user per month, plus a 14-day trial.
- The operator is Excalidraw s.r.o. in Brno, under Czech law.
Where Excalidraw falls short
- The privacy policy puts Excalidraw+ servers in the United States.
- A self-hosted copy cannot share boards without the separate collaboration server.
- The free tier holds a single scene.
- Prices are quoted in USD only.
Standout feature. Excalidraw is the only open-source tool in this comparison that offers end-to-end encrypted collaboration in its free editor.
Berlin, Germany
Founded 2010
Free and open source
Demo on request
Best for: Public bodies and offices that want simple diagrams in a free office suite that works entirely offline
LibreOffice is a free office suite made up of Writer, Calc, Impress, Draw, Base and Math, and its Draw module is the part relevant to diagrams. It installs locally, needs no account and, according to the site, transmits nothing, which keeps the data assessment short. Several European public administrations have standardised on it.
The Document Foundation, a non-profit incorporated in Berlin, develops it, funded by donations and corporate contributors rather than licence sales, and the suite dates from 2010. The trade-offs the site admits are OOXML fidelity that is good but not exact, a dated interface and real-time collaboration that needs Collabora Online.
What LibreOffice does well
- Complete suite: Writer, Calc, Impress, Draw, Base, Math
- Free, offline, no account and nothing transmitted
- Non-profit foundation in Berlin, no upsell path
- Open formats guarantee long-term document access
- Widely adopted by European public administrations
Where LibreOffice falls short
- OOXML fidelity good but not exact on complex layouts
- Real-time collaboration requires Collabora Online
- Interface looks dated next to subscription suites
- No first-party cloud or mobile editing story
Standout feature. LibreOffice offers diagram drawing inside a suite that sends no data anywhere and whose open formats stay readable without a vendor.
Leipzig, Germany
Professional $19 per month, Teams from $69 per month for 5 seats, Enterprise on request, 14-day free trial (default price view, a EUR and USD switch is offered)
Demo on request
Best for: Presentation-ready roadmaps, timelines and business graphics rather than technical diagrams
Vizzlo creates charts and business graphics: the home page says users paste data, upload a file or type it in. It offers 120+ chart types and works in Google Slides and PowerPoint as well as in the browser and a desktop app. Shared colours, fonts and templates keep graphics on brand, and charts can link to cloud files and update automatically.
The terms describe the service as operated by Vizzlo GmbH, and the About page gives Spinnereistraße 7, 04179 Leipzig, Amtsgericht Leipzig HRB 31786, with Robert Lillack as management. Professional costs $19 per month and Teams starts at $69 per month for five seats on the default view, with a 14-day free trial. Enterprise adds single sign-on and audit logs, and data location is not stated.
What Vizzlo does well
- 120+ chart types
- Works in Google Slides and PowerPoint
- Shared brand styling across a team
- German company with trade-register entry
- 14-day free trial
Where Vizzlo falls short
- Not a technical diagram editor
- Data location not stated
- No permanent free plan shown
- Default prices in USD
Standout feature. Vizzlo is the only tool here built to produce roadmaps and chart graphics directly inside slide decks.
