If you care about privacy, hate subscription fees, or simply want full control over your data, open source time tracking software is a compelling choice. Unlike proprietary tools that lock your time data in someone else's cloud, open source trackers let you inspect the code, host it on your own server, and customize it to fit your workflow exactly.
The demand for transparent, self-hosted alternatives has surged in recent years. Whether you are a freelancer who needs invoicing, a developer who wants automatic coding metrics, or a team lead looking for a free open source time tracking solution that scales, there is a tool built for your use case. This guide breaks down the seven best open source time trackers available today, compares their features side by side, and helps you choose the right one.
What to Look for in Open Source Time Tracking Software
Before diving into individual tools, it helps to know what separates a good open source time tracker from a mediocre one. Here are the criteria we used to evaluate each option:
- Active development. An open source project is only as good as its community. Look for regular commits, recent releases, and responsive maintainers.
- Self-hosting options. The ability to deploy on your own server (via Docker, for example) is a core benefit of going open source. Some tools also offer a managed cloud option for convenience.
- Core tracking features. At minimum, you need start/stop timers, manual time entry, project organization, and basic reporting.
- Privacy and data ownership. Your time data should stay under your control, whether that means local storage, your own database, or encrypted sync.
- Platform support. Cross-platform availability (web, desktop, mobile) matters for consistent tracking throughout the day.
- Extras. Invoicing, team management, integrations with project management tools, and API access can make or break a tool for professional use.
7 Best Open Source Time Tracking Tools
1. Kimai
Kimai is arguably the most mature and feature-rich open source time tracker on the market. Built with Symfony (PHP), it targets freelancers, agencies, and companies that need professional-grade timesheet management.
Key features:
- Unlimited users, projects, and activities
- Built-in invoicing with customizable templates
- SAML, LDAP, and database authentication
- Two-factor authentication and role-based permissions
- Multi-currency support with time and money budgets
- REST API and a plugin ecosystem for extending functionality
- Docker-based self-hosting or a managed cloud option at kimai.cloud
Best for: Teams and agencies that need invoicing, client management, and granular permissions. If you want a self-hosted time tracking platform that replaces tools like Harvest or Toggl, Kimai is the first place to look.
License: AGPL-3.0
2. Solidtime
Solidtime is a newer entrant that has quickly earned attention for its clean, modern interface. Built with Laravel and Vue.js, it feels like a polished SaaS product while remaining fully open source.
Key features:
- Modern UI with intuitive time entry and project management
- Client management and billable rates at multiple levels
- Invoice generation with automatic total calculation
- Import from Toggl, Clockify, and CSV
- Desktop apps for macOS, Windows, and Linux
- Self-hostable via Docker or deployable on the managed cloud
Best for: Freelancers and small agencies who want the look and feel of a commercial tracker without the recurring cost. Solidtime is especially appealing if you are migrating from Toggl or Clockify and want to bring your data along.
License: AGPL-3.0
3. ActivityWatch
ActivityWatch takes a fundamentally different approach: it tracks your computer usage automatically in the background, logging which applications and websites you use throughout the day. No manual timers required.
Key features:
- Fully automatic tracking of active windows, browser tabs, and AFK status
- All data stored locally on your device by default
- Extensible watcher and plugin system
- Cross-platform: Windows, macOS, Linux, and Android
- Web-based dashboard for visualization and analysis
- REST API for custom integrations
Best for: Individuals who want a passive, privacy-first picture of how they spend time on their computer. ActivityWatch does not do invoicing or team management. It is a personal analytics tool, and it does that job very well.
License: MPL-2.0
4. Super Productivity
Super Productivity combines task management, time tracking, and focus tools into a single open source application. It works offline by default and stores everything locally.
Key features:
- Integrated task/to-do list with time tracking per task
- Pomodoro timer and timeboxing
- Break reminders and anti-procrastination prompts
- Sync via file, WebDAV (Nextcloud), or Dropbox with optional encryption
- Integrations with Jira, GitLab, GitHub, and OpenProject
- Available on Windows, macOS, Linux, Android, and as a web app
Best for: Developers and knowledge workers who want a combined task manager and time tracker that respects their privacy. Super Productivity shines when you need focus tools alongside your time data.
License: MIT
5. WakaTime
WakaTime is purpose-built for developers. Its open source IDE plugins automatically track coding activity across editors like VS Code, IntelliJ, Vim, and dozens more.
Key features:
- Automatic time tracking triggered by coding activity
- Per-project, per-language, and per-file breakdowns
- Leaderboards and goals for motivation
- AI code time detection
- Open source plugins (BSD License) for 60+ IDEs
- Dashboard for visualizing coding patterns
Important note: While WakaTime's plugins are open source, the backend dashboard is a freemium SaaS product. For a fully open source alternative, check out Hackatime, which is WakaTime-compatible and self-hostable.
Best for: Software developers who want granular insight into their coding time without changing their workflow.
License: BSD (plugins); proprietary (backend)
6. Traggo
Traggo is a minimalist, tag-based time tracking server written in Go. Instead of organizing time around projects and tasks, everything revolves around tags, giving you flexible categorization.
Key features:
- Tag-based time tracking with no rigid project hierarchy
- Self-hosted via a single binary or Docker
- Simple, lightweight web UI
- GraphQL API
- Low resource usage, suitable for Raspberry Pi and similar devices
Caveat: Traggo's development has slowed considerably in recent years. There is no paid support and documentation is limited. It remains a solid choice for personal use if you value its tag-based philosophy, but it may not be the best pick for a team.
Best for: Individuals who prefer a flexible, tag-driven approach to categorizing their time and want something extremely lightweight to self-host.
License: GPL-3.0
7. OpenProject
OpenProject is a full-featured project management platform that includes built-in time tracking. If your team already uses or needs project management capabilities like Gantt charts, agile boards, and work packages, OpenProject bundles time tracking into the larger workflow.
Key features:
- Time and cost tracking tied to work packages
- Gantt charts, Kanban boards, and backlog management
- Team scheduling and resource management
- Self-hosted (Community Edition is free) or cloud-hosted
- LDAP and SSO authentication
- REST API
Best for: Teams that need project management first and time tracking second. OpenProject is overkill if you only need a time tracker, but it is excellent if you want everything in one open source platform.
License: GPL-3.0
Open Source Time Tracking Software: Feature Comparison
| Feature | Kimai | Solidtime | ActivityWatch | Super Productivity | WakaTime | Traggo | OpenProject |
|---|---|---|---|---|---|---|---|
| Tracking type | Manual | Manual | Automatic | Manual + Timer | Automatic (code) | Manual | Manual |
| Self-hosted | Yes | Yes | Yes (local) | Yes (local/WebDAV) | Plugins only | Yes | Yes |
| Invoicing | Yes | Yes | No | No | No | No | No |
| Team support | Yes | Yes | No | No | Yes (paid) | No | Yes |
| Mobile app | Yes | No | Android | Android | No | No | No |
| Desktop app | No | Yes | Yes | Yes | IDE plugins | No | No |
| Offline mode | No | No | Yes | Yes | Yes | No | No |
| API | REST | REST | REST | No | REST | GraphQL | REST |
| Active development | High | High | Moderate | High | High | Low | High |
| License | AGPL-3.0 | AGPL-3.0 | MPL-2.0 | MIT | BSD/Proprietary | GPL-3.0 | GPL-3.0 |
Open Source vs. Proprietary Time Tracking: Pros and Cons
Choosing between open source and proprietary time tracking software comes down to your priorities.
Advantages of open source
- Full data ownership. Your time data lives on your server or your device. No vendor lock-in, no surprise policy changes, and no risk of a company shutting down and taking your data with it.
- Transparency. You can audit the code to verify that no data is being sent to third parties.
- Cost. Most open source trackers are free to use. You pay only for hosting if you self-host, or for optional managed plans.
- Customization. Modify the software to match your exact workflow, add integrations, or build custom reports.
Disadvantages of open source
- Setup complexity. Self-hosting requires server administration skills. Docker helps, but it is still more effort than signing up for a SaaS tool.
- Support. Community support can be inconsistent. Paid support is sometimes available but not guaranteed.
- Polish and UX. Many open source tools lag behind commercial products in design and user experience, though projects like Solidtime are closing that gap.
- Feature gaps. Advanced features like AI-powered insights, automatic categorization, and native integrations are more common in proprietary tools.
The middle ground: privacy-focused proprietary tools
Not every proprietary tool sends your data to the cloud. Chronoid, for example, shares the core philosophy of open source time tracking: your data stays 100% on your Mac, never uploaded to any server. It combines automatic time tracking, a built-in Pomodoro timer, and a website blocker in a native macOS app. If you want the privacy benefits of open source without the overhead of self-hosting, it is worth considering. You can download Chronoid here.
How to Choose the Right Open Source Time Tracker
Use this quick decision framework:
- Need invoicing and team management? Start with Kimai or Solidtime.
- Want automatic personal tracking? ActivityWatch or Super Productivity.
- Developer looking for coding metrics? WakaTime plugins with Hackatime backend.
- Need project management + time tracking? OpenProject.
- Want something minimal and tag-based? Traggo.
- Want automatic tracking on Mac with zero setup? Chronoid runs natively on macOS with all data stored locally.
Frequently Asked Questions
Is open source time tracking software really free?
The software itself is free to download and use. However, if you self-host, you will pay for server infrastructure (a basic VPS starts around $5/month). Some projects like Kimai and Solidtime also offer paid managed hosting if you prefer not to handle server administration.
Can I use open source time trackers for client billing?
Yes. Kimai and Solidtime both include invoicing features that let you generate invoices directly from tracked time. You can set billable rates per project, client, or user and export professional invoices in PDF format.
Are self-hosted time trackers secure?
Security depends on your server setup. Open source software benefits from community code review, which can surface vulnerabilities faster than closed-source alternatives. However, you are responsible for keeping the software updated, configuring HTTPS, managing backups, and securing access. If security maintenance is a concern, consider a tool that stores data locally on your device rather than on a server.
What is the best open source time tracker for a small team?
Kimai is the strongest choice for small teams. It supports unlimited users, offers role-based permissions, handles multiple projects and clients, and includes built-in invoicing. Solidtime is a strong alternative if you prefer a more modern interface.
Can open source time tracking replace tools like Toggl or Clockify?
For most use cases, yes. Kimai and Solidtime offer comparable feature sets to Toggl and Clockify, including project management, reporting, and team collaboration. The main trade-off is that you need to self-host or pay for their managed cloud services, and the mobile app ecosystem is less mature.
Conclusion
Open source time tracking software has matured significantly. Tools like Kimai and Solidtime rival commercial products in features, while ActivityWatch and Super Productivity offer privacy-first automatic tracking that many paid tools cannot match. The right choice depends on whether you need team features, automatic tracking, developer metrics, or full project management.
If the self-hosting requirement feels like too much overhead but you still want local, private time tracking on your Mac, try Chronoid for free. It tracks your time automatically, keeps everything on your device, and includes focus tools like a Pomodoro timer and website blocker built right in.
Cover photo by Hitesh Choudhary on Unsplash