Kimai is an open-source time-tracking application that began in 2006 and has been led since 2009 by Vienna-based developer Kevin Papst, who rewrote the codebase and grew it into a leading open-source time-tracking tool used by freelancers, agencies, and companies.
The AGPL-licensed core is free to self-host with unlimited users, while Kimai Cloud offers a fully managed, GDPR-compliant SaaS alternative hosted in Germany for teams that don't want to run their own server.
Time is tracked against a hierarchy of customers, projects, and activities, and invoices are generated directly from recorded hours, removing manual estimation and spreadsheet work.
Key Features
Kimai includes an extensive JSON API, two-factor authentication, and single sign-on via LDAP and SAML with providers like Google Workspace and Azure AD.
Official plugins extend the core with advanced invoicing, custom reporting, multi-step approval workflows, and expense tracking.
Kimai Cloud's Professional tier adds working-hour accounts, vacation and sick-leave tracking, a customer portal, kiosk mode, daily backups, and custom domains with SSL.
Pricing
Self-hosted Kimai is entirely free under the AGPL license with no user limits. Kimai Cloud is priced per user per month, with a Standard plan from EUR 2.99/user/month (annual) and a Professional plan from EUR 3.99/user/month (annual), plus a discounted EUR 0.99/user/month rate for non-profits.
All Kimai Cloud plans include a 30-day free trial, no setup fees, and month-to-month cancellation.
Key Features
Time tracking by customer, project, and activity — Organizes logged hours into a clear hierarchy for accurate reporting and invoicing.
Automated invoicing — Generates client invoices directly from recorded billable hours.
JSON API — Extensive API for reading and writing timesheet data to integrate with other tools.
Two-factor authentication and SSO — TOTP-based 2FA plus LDAP and SAML single sign-on support.
Plugin ecosystem — Official plugins add advanced invoicing, custom reports, approval workflows, and expense tracking.
Multi-user support — Unlimited users with role-based permissions in self-hosted installations.
Kimai Cloud hosting — Fully managed SaaS option hosted in Germany with GDPR compliance.
Kiosk mode and customer portal — Shared time-clock device mode and a client-facing portal on the Professional plan.
Pros & Cons
Pros
Free, self-hostable open-source core with no user limits
Low per-seat pricing on Kimai Cloud compared to many SaaS competitors
Extensive JSON API and plugin ecosystem for customization
GDPR-compliant hosting option in Germany
Active development with a long project history since 2006
Cons
Self-hosting requires server setup and maintenance effort
Advanced features like approvals and expense tracking require the Professional plan or plugins
Smaller company behind the product compared to large SaaS time-tracking vendors
Interface may feel less polished than premium commercial competitors
Kimai Cloud Standard EUR 2.99/user/month (annual), EUR 3.99 monthly Monthly or annual
Kimai Cloud Professional EUR 3.99/user/month (annual), EUR 4.99 monthly Monthly or annual
Frequently Asked Questions
Is Kimai free?
Yes, the self-hosted core is free and open source under the AGPL license. Kimai Cloud is a paid managed hosting option starting at EUR 2.99 per user per month.
Who created Kimai?
Kimai began in 2006 under Torsten Hoeltge, and has been developed since 2009 by Vienna-based developer Kevin Papst.
What is the difference between self-hosted Kimai and Kimai Cloud?
Self-hosted Kimai is free open-source software you run on your own server, while Kimai Cloud is a paid, fully managed SaaS version hosted in Germany.
Does Kimai support invoicing?
Yes, Kimai generates invoices directly from recorded billable hours, with advanced invoicing templates available via plugins or the Professional Cloud plan.
Does Kimai offer a free trial?
Kimai Cloud plans include a 30-day free trial with no setup fees.
What are alternatives to Kimai?
Common alternatives include Toggl Track, Clockify, Harvest, and TimeCamp.