Flagsmith vs GrowthBook
Both are alternatives to LaunchDarkly. Here's how they stack up — verified facts, no spin.
Also searched as GrowthBook vs Flagsmith — same comparison, one verdict.
Flagsmith
BSD-licensed flags with remote config, and no copyleft to reason about.
Flagsmith covers feature flags, remote configuration and A/B testing under BSD-3-Clause — the most permissive licence in this comparison, which removes the legal reading that AGPL requires. It self-hosts on Docker or Kubernetes, supports multiple environments and organisations natively, and its edge API keeps evaluation latency low without you building a caching layer. Around 6.5k stars. Its remote-config support is the underrated part: shipping a configuration value to clients without a release is the same mechanism as a flag, and having both in one tool removes a category of bespoke plumbing.
GrowthBook
Flags plus a real statistics engine — the experimentation answer.
GrowthBook is the option to look at when the reason you want flags is experiments rather than toggles. It runs A/B tests against your existing data warehouse — Snowflake, BigQuery, Redshift, Postgres — so the analysis happens where your data already lives instead of in a second copy, and it offers Bayesian and frequentist statistics rather than one opinionated method. Around 8.1k stars. The licence needs stating precisely: the core is MIT, but three enterprise directories are carved out under a separate commercial licence, so it is MIT-with-exceptions rather than plain MIT.
Side by side
| Flagsmith | GrowthBook | |
|---|---|---|
| Sovereignty Score | 90 | 83 |
| Open source | Yes | Yes |
| Self-hostable | Yes | Yes |
| Local-first | Yes | Yes |
| License | BSD-3-Clause (open core; paid hosted and enterprise tiers) | MIT core, with enterprise directory carve-outs |
| Pricing | Open source free and self-hostable. Hosted plans have a free tier and paid tiers above it. | Self-hostable core free. Cloud and enterprise tiers are paid. |
Flagsmith edges it on the Sovereignty Score, but the right pick depends on the trade-offs below.
Flagsmith
Strengths
- +BSD-3-Clause — the most permissive licence here, no copyleft to interpret
- +Feature flags and remote config in one product
- +Multi-environment and multi-organisation support built in, not bolted on
- +Edge API keeps evaluation fast without custom caching
Trade-offs
- −Smaller community than Unleash and fewer third-party integrations
- −Experimentation is basic next to LaunchDarkly
- −Advanced features are reserved for the paid tiers
- −Self-hosted deployment needs Postgres and some tuning at scale
GrowthBook
Strengths
- +Genuine statistics engine — Bayesian and frequentist, not a toggle with a chart
- +Runs experiments against your existing warehouse, no data duplication
- +Warehouse-native means no second source of truth to reconcile
- +Self-hostable with a real free path
Trade-offs
- −Enterprise directories are carved out of the MIT licence
- −Heavier to set up than the pure flag tools — you need a warehouse
- −Flag management is less polished than Unleash's
- −Overkill if you only want to turn features on and off
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Facts verified 2026-07-31. Licenses and pricing change — spotted something out of date? That's a correction we want.