head to head · open source
ActivityWatch vs Kimai
ActivityWatch has 19,481 GitHub stars, 1,068 forks, 186 open issues and last shipped 2 days ago. Kimai has 5,129 stars, 878 forks, 350 open issues and last shipped yesterday. ActivityWatch leads on adoption by 280% (19,481 vs 5,129 stars). ActivityWatch is written in Python under MPL-2.0; Kimai is written in PHP under AGPL-3.0. ActivityWatch has attracted 5% as many forks as stars, Kimai 17%. Kimai was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 3 topic tags (time-tracker, time-tracking, timetracker), so they are genuine substitutes rather than adjacent tools.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| ActivityWatch | Kimai | |
|---|---|---|
| GitHub stars | ★ 19K | ★ 5.1K |
| License | MPL-2.0 | AGPL-3.0 |
| Written in | Python | PHP |
| Last push | 2026-11-01 | 2026-11-02 |
| Forks | ⑂ 1.1K | ⑂ 878 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick ActivityWatch if
- You weight community size — 19K stars and counting
- You want the MPL-2.0 license terms
- Your stack matches Python
- You value the larger contributor base for long-term maintenance
pick Kimai if
- You want the Kimai feature set and don't need the biggest community
- You prefer the AGPL-3.0 license terms
- Your stack matches PHP
- You evaluated both and Kimai fits your workflow better
About ActivityWatch
Records what you do so that you can know how you've spent your time . All in a secure way where you control the data . Website — Forum — Documentation — Releases Contributor stats — CI overview Do you want to receive email updates on major announcements? Signup for the newsletter! Table of Contents About Screenshots Is this yet another time tracker? Feature comparison Installation & Usage About this repository Server Watchers Libraries Contributing About The goal of ActivityWatch is simple: Enable the collection of as much valuable lifedata as possible without compromising user privacy. We've worked towards this…
read the full ActivityWatch overview →
About Kimai
Kimai 1 Open Source Time Tracker Kimai is a professional grade time tracking application, free and open source. It handles use cases of freelancers as well as companies with dozens or hundreds of users. Kimai was build to track your project times and ships with many advanced features, including but not limited to: JSON API, invoicing, data exports, multi timer and punch in punch out mode, tagging, multi user multi timezones multi language (over 30 translations existing!), authentication via SAML/LDAP/Database, two factor authentication (2FA) with TOTP, customizable role and team permissions, responsive design…
read the full Kimai overview →
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Frequently asked questions
Is ActivityWatch or Kimai more popular?
ActivityWatch has 19,481 GitHub stars and Kimai has 5,129. ActivityWatch has the larger community by that measure.
Are ActivityWatch and Kimai free?
Both are open source. ActivityWatch is licensed under MPL-2.0 and Kimai under AGPL-3.0. Neither carries a licence fee.
What is the difference between ActivityWatch and Kimai?
ActivityWatch is written in Python and Kimai in PHP. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, ActivityWatch or Kimai?
Choose ActivityWatch if you want the larger community (19,481 stars) or its MPL-2.0 licence terms. Choose Kimai if its feature set, stack or AGPL-3.0 licence fits better. Both are self-hostable.