OSI-licensed open source
Time trackers record where hours go, either automatically by watching active windows or manually via timers and timesheets. Open-source options keep tracking data local or self-hosted, which suits freelancers, developers and teams who do not want to ship activity data to a third party.
This page lists OSI-licensed tools that run on Windows, either as desktop apps (ActivityWatch, Super Productivity, Tockler) or as self-hosted web apps you open from Windows browsers (Kimai, TimeTagger, solidtime, Traggo). Timewarrior is omitted because its page did not mention Windows support.
Tools, licences and pricing checked against vendor and repository pages on November 7, 2026.
| Tool | Best for | Pricing | Licence |
|---|---|---|---|
| ActivityWatch | Automatic, private activity tracking | Free, open source | MPL-2.0 |
| Kimai | Teams and freelancers needing timesheets and invoicing | Free, open source (self-hosted); SaaS, See vendor pricing | AGPL-3.0 |
| Super Productivity | Task-linked time tracking for developers | Free, open source | MIT |
| TimeTagger | Simple tag-based tracking | Free, open source (self-hosted); hosted plans, See vendor pricing | GPL-3.0 |
| solidtime | Freelancers and agencies moving off Toggl or Clockify | Free, open source (self-hosted); cloud, See vendor pricing | AGPL-3.0 |
| Traggo | Tag-based tracking with dashboards | Free, open source | GPL-3.0 |
| Tockler | Passive app usage tracking on Windows | Free, open source | GPL-2.0-only |
Best for: Automatic, private activity tracking · Free, open source
ActivityWatch is a free, open-source automated time tracker that records active applications, browser tabs and keyboard and mouse activity to detect idle time, storing data on your own machine. It runs on Windows, macOS, Linux and Android.
Best for: Teams and freelancers needing timesheets and invoicing · Free, open source (self-hosted); SaaS, See vendor pricing
Kimai is an open-source, web-based, multi-user time-tracking application offered on-premise or as SaaS, handling timesheets, reporting, invoicing and exports. It is built on PHP and Symfony with MariaDB or MySQL.
Best for: Task-linked time tracking for developers · Free, open source
Super Productivity is a todo list app with timeboxing and time tracking plus integrations for Jira, GitLab, GitHub and OpenProject. It runs on Windows, Linux, macOS, Android, iOS and in the browser.
Best for: Simple tag-based tracking · Free, open source (self-hosted); hosted plans, See vendor pricing
TimeTagger is a web-based open-source time tracker that runs locally or on a server, with an interactive timeline, tags instead of projects, and PDF and CSV reports. It is built on Python with SQLite.
Best for: Freelancers and agencies moving off Toggl or Clockify · Free, open source (self-hosted); cloud, See vendor pricing
solidtime is a self-hostable open-source tool for tracking work hours aimed at freelancers and agencies, with projects, tasks, clients, billable rates and multiple organisations. It can import from Toggl, Clockify and CSV.
Best for: Tag-based tracking with dashboards · Free, open source
Traggo is a self-hosted time tracker that records time as tagged spans rather than tasks, with customisable tags, dashboards and list and calendar views.
Best for: Passive app usage tracking on Windows · Free, open source
Tockler is a free open-source desktop app that records which application windows you use and whether the computer is active, idle or offline. It runs on Windows, macOS and Linux with timelines and statistics.
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| If you need… | Start with |
|---|---|
| Automatic tracking with local data | ActivityWatch, Tockler |
| Timesheets with invoicing for teams | Kimai |
| Task manager with built-in timers | Super Productivity |
| Lightweight tag-based tracking | TimeTagger, Traggo |
| Freelance billing and Toggl migration | solidtime |
Quick answers to common questions
ActivityWatch and Super Productivity run natively on Windows; Kimai and solidtime run in a browser after self-hosting.
Yes, any self-hosted web tracker is usable from a Windows browser, but you need a server or local host to run it.
ActivityWatch stores data on your own machine; still review each tool's settings.
Its page did not list Windows support, so it is not included.
List it on TechLogHub and we'll review it for this guide.
