Which open source licence matters for a website owner?
For analytics you run on your own server, the differences are small. Plausible, Pirsch and Swetrix use AGPL, which requires anyone who offers a modified version as a service to publish their changes, and Koko Analytics uses GPL-3.0. Counter.dev uses MIT, which allows almost any reuse. None of them stops you from running the software for your own site.
The difference appears if you plan to build something on top. A company that wants to embed analytics in a commercial product has to respect the AGPL terms, whereas MIT leaves room. For plain measurement of your own website, pick on features and hosting, not on the licence letters.
Should you self-host or pay for the hosted version?
Self-hosting removes the vendor from the data path, and for Plausible and Pirsch the tool pages say the self-hosted version has the same features as the cloud one. What you take on is the server: updates, backups, uptime and a database that grows with traffic. A small site on a tidy VPS manages this easily, while a site with heavy traffic needs someone who owns it.
The hosted plans are inexpensive enough that the comparison is rarely about money. Plausible starts at about €9 a month and Pirsch at about €4. Self-hosting is worth it for data control or policy reasons, and the hosted plan is worth it when nobody wants to be on call for an analytics database.
Does open source mean you can skip the cookie banner?
No, those are separate questions. The licence says nothing about what the script collects. Plausible, Pirsch, Counter.dev and Koko Analytics all state that they use no cookies, and Plausible states no personal data is collected, which is why they say no consent banner is needed. Swetrix describes itself as cookieless.
Check the setup, not just the product. Features such as session replays, as offered by Swetrix, record individual behaviour and need their own assessment. The legal position depends on your configuration and your country, so confirm it with your data protection adviser.
What changes when you migrate away from Google Analytics?
Expect fewer numbers. These tools report visitors, pageviews, referrers, goals and basic events, and they leave out deep segmentation and audiences for advertising. Plausible says plainly that it does not import Google Analytics history, so export the old reports before you switch off the old property.
Run both side by side for a few weeks. Counts will differ, because cookieless tools and consent-based tools measure visitors differently, and your baseline resets on the day you switch. Agree internally which numbers count from then on.
When is open source the wrong choice for analytics?
When you need what these tools omit. Heatmaps, A/B testing and detailed attribution are not part of Plausible or Pirsch, and Counter.dev has no events at all. Teams that need those features are better served by the broader suites on the category page.
It is also wrong if the licence is the only reason you picked the tool. A free self-hosted install that nobody updates is a liability, and a single-maintainer project like Counter.dev should not carry reporting that the business depends on.
