Flagsmith

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Introduction

Flagsmith is an open-source feature flag platform with remote config and experimentation, available self-hosted or in the cloud. The core is BSD-3-Clause licensed.

Flags can be boolean or carry values for remote configuration. Segments target users by traits, and percentage splits enable staged rollouts and multivariate tests. Environments separate development, staging and production, and SDKs cover popular server, web and mobile platforms. Local evaluation mode in server SDKs avoids a network call per check, and Flagsmith also supports OpenFeature.

In the quality loop Flagsmith decouples deploy from release, so features can be tested in production with limited audiences.

The source code is at Flagsmith/flagsmith on GitHub under the BSD-3-Clause licence, with about 7,100 stars; the most recent commit was on 10 November 2026.

Features

1. Flags and remote config: Boolean and value flags.
2. Segments: Trait-based targeting.
3. Multivariate flags: Percentage splits for tests.
4. Environments: Separate configs per stage.
5. Local evaluation: In-memory checks in server SDKs.
6. Self-hosting: Docker and Kubernetes deployment.

Pros

1. Permissive licence: BSD-3-Clause core.
2. Free to use: Open source under the BSD-3-Clause licence, so the core tool costs nothing to use.
3. Actively maintained: The repository had commits as recent as 10 November 2026.
4. Community: About 7,100 GitHub stars.

Cons

1. Enterprise features gated: RBAC and audit features vary by plan.
2. API call pricing: Cloud plans meter API calls.
3. Analysis is basic: Use an analytics tool for deep experiment stats.

Usage and Links (Example)

docker run -p 8000:8000 flagsmith/flagsmith:latest

from flagsmith import Flagsmith
fs = Flagsmith(environment_key="ser.xxxx", enable_local_evaluation=True)
flags = fs.get_identity_flags("user-42", traits={"plan": "pro"})
if flags.is_feature_enabled("new_search"): ...

Resources:

• Flagsmith website
• GitHub repository

Pricing

Flagsmith’s open-source edition is free to self-host, and its cloud has a free plan and a 14-day free trial of paid plans. Paid plans are priced per member per month, and additional API calls start at $50 per million per month, decreasing with volume.

Recommended for?

1. Teams wanting open-source flags with a permissive licence.
2. Mobile apps using remote config.

Conclusion

Flagsmith is a flexible, permissively licensed flag and remote-config platform.

Use local evaluation for performance-sensitive services.

On CheckOps, Flagsmith is filed under the Release & CI gates and Production monitoring & observability stages. Related tools listed here include LaunchDarkly, Unleash, GrowthBook, OpenFeature, Flipt and Statsig. Before standardising on one, compare recent maintenance activity, the pricing model as your usage grows, and the integrations you rely on today. Information on this page was verified against the official website, documentation and repository on 11 November 2026.