head to head · open source
Cap vs Flagsmith
Cap has 8,236 GitHub stars, 637 forks, 10 open issues and last shipped 5 days ago. Flagsmith has 6,638 stars, 595 forks, 711 open issues and last shipped yesterday. Cap leads on adoption by 24% (8,236 vs 6,638 stars). Cap is written in JavaScript under a custom or non-standard licence; Flagsmith is written in Python under BSD-3-Clause. Cap has attracted 8% as many forks as stars, Flagsmith 9%. Flagsmith was the more recently maintained of the two, and both are self-hostable with no licence fee.
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
| Cap | Flagsmith | |
|---|---|---|
| GitHub stars | ★ 8.2K | ★ 6.6K |
| License | Custom / other | BSD-3-Clause |
| Written in | JavaScript | Python |
| Last push | 2026-10-29 | 2026-11-02 |
| Forks | ⑂ 637 | ⑂ 595 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Cap if
- You weight community size — 8.2K stars and counting
- You want the Custom / other license terms
- Your stack matches JavaScript
- You value the larger contributor base for long-term maintenance
pick Flagsmith if
- You want the Flagsmith feature set and don't need the biggest community
- You prefer the BSD-3-Clause license terms
- Your stack matches Python
- You evaluated both and Flagsmith fits your workflow better
About Cap
Cap Cap is a lightweight, modern open source CAPTCHA alternative using proof of work and instrumentation challenges . It's fast, private, and extremely simple to integrate. Documentation Read the docs , try the demo or deploy on Railway What is Cap? Cap replaces visual captchas with modern, accessible and privacy preserving challenges. No images, no tracking, no dependencies, works everywhere. The default way to use Cap is with the Standalone Docker container. Learn more about how Cap works Why Cap? 250x smaller than hCaptcha 20kb, zero dependencies, loads in milliseconds Privacy first Cap doesn't send any…
About Flagsmith
Try our interactive demo Flagsmith is an Open Source Feature Flagging Tool to Ship Faster & Control Releases Change the way your team releases software. Roll out, segment, and optimise—with granular control. Stay secure with on premise and private cloud hosting. Feature flags: Release features behind the safety of a feature flag Make changes remotely: Easily toggle individual features on and off, and make changes without deploying new code A/B testing: Use segments to run A/B and multivariate tests on new features Segments: Release features to beta testers, collect feedback, and iterate Organisation management…
read the full Flagsmith overview →
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Frequently asked questions
Is Cap or Flagsmith more popular?
Cap has 8,236 GitHub stars and Flagsmith has 6,638. Cap has the larger community by that measure.
Are Cap and Flagsmith free?
Both are open source. Cap has no licence declared in this registry, and Flagsmith is licensed under BSD-3-Clause. Both are free to self-host.
What is the difference between Cap and Flagsmith?
Cap is written in JavaScript and Flagsmith in Python. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Cap or Flagsmith?
Choose Cap if you want the larger community (8,236 stars) or its Custom / other licence terms. Choose Flagsmith if its feature set, stack or BSD-3-Clause licence fits better. Both are self-hostable.