head to head · open source
Cap vs Abby
Cap has 7,798 GitHub stars, 579 forks, 10 open issues and last shipped 2 days ago. Abby has 166 stars, 30 forks, 31 open issues and last shipped 1.2 years ago. Cap leads on adoption by 4,598% (7,798 vs 166 stars). Cap is written in JavaScript under a custom or non-standard licence; Abby is written in TypeScript under AGPL-3.0. Cap has attracted 7% as many forks as stars, Abby 18%. Cap 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 | Abby | |
|---|---|---|
| GitHub stars | ★ 7.8K | ★ 166 |
| License | Custom / other | AGPL-3.0 |
| Written in | JavaScript | TypeScript |
| Last push | 2026-09-16 | 2025-07-24 |
| Forks | ⑂ 579 | ⑂ 30 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Cap if
- You weight community size — 7.8K 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 Abby if
- You want the Abby feature set and don't need the biggest community
- You prefer the AGPL-3.0 license terms
- Your stack matches TypeScript
- You evaluated both and Abby fits your workflow better
About Cap
Cap is a free, open source, self hosted CAPTCHA replacement that swaps visual puzzles for proof of work and instrumentation challenges, built for developers and site operators who want anti bot protection without shipping their visitors' data to a third party service.
About Abby
Abby is an open source, TypeScript feature management and A/B testing platform that pairs statically typed SDKs for core JavaScript, React, Next.js, Angular and Svelte with a dashboard the non developers on a team can use, aimed at developers who want feature flags and remote config without sending user data to a third party.
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Frequently asked questions
Is Cap or Abby more popular?
Cap has 7,798 GitHub stars and Abby has 166. Cap has the larger community by that measure.
Are Cap and Abby free?
Both are open source. Cap has no licence declared in this registry, and Abby is licensed under AGPL-3.0. Both are free to self-host.
What is the difference between Cap and Abby?
Cap is written in JavaScript and Abby in TypeScript. 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 Abby?
Choose Cap if you want the larger community (7,798 stars) or its Custom / other licence terms. Choose Abby if its feature set, stack or AGPL-3.0 licence fits better. Both are self-hostable.