head to head · open source
GrowthBook vs Flagsmith
GrowthBook has 8,376 GitHub stars, 849 forks, 793 open issues and last shipped yesterday. Flagsmith has 6,559 stars, 568 forks, 711 open issues and last shipped yesterday. GrowthBook leads on adoption by 28% (8,376 vs 6,559 stars). GrowthBook is written in TypeScript under a custom or non-standard licence; Flagsmith is written in Python under BSD-3-Clause. GrowthBook has attracted 10% as many forks as stars, Flagsmith 9%. GrowthBook 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
| GrowthBook | Flagsmith | |
|---|---|---|
| GitHub stars | ★ 8.4K | ★ 6.6K |
| License | Custom / other | BSD-3-Clause |
| Written in | TypeScript | Python |
| Last push | 2026-09-17 | 2026-09-17 |
| Forks | ⑂ 849 | ⑂ 568 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick GrowthBook if
- You weight community size — 8.4K stars and counting
- You want the Custom / other license terms
- Your stack matches TypeScript
- 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 GrowthBook
GrowthBook is an open source platform for feature flags, A/B experimentation, and product analytics that product, data, and platform teams can either consume through a hosted cloud account or run entirely on their own infrastructure.
read the full GrowthBook overview →
About Flagsmith
Flagsmith is an open source feature flag and remote configuration platform, written in Python and released under the BSD 3 Clause licence, for engineering teams that need to toggle, segment and roll out features across web, mobile and server side applications without deploying new code.
read the full Flagsmith overview →
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Frequently asked questions
Is GrowthBook or Flagsmith more popular?
GrowthBook has 8,376 GitHub stars and Flagsmith has 6,559. GrowthBook has the larger community by that measure.
Are GrowthBook and Flagsmith free?
Both are open source. GrowthBook 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 GrowthBook and Flagsmith?
GrowthBook is written in TypeScript 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, GrowthBook or Flagsmith?
Choose GrowthBook if you want the larger community (8,376 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.