Flagsmith

Open-source feature flags and remote config, available as cloud, private cloud or self-hosted.

Open sourceSelf-hostableProduct analytics tools

Verified facts: 4 of 4
Alternatives ranked: 5
Approved reviews: 0
Visits sent from here: 0

About Flagsmith

Flagsmith is an open-source feature flag and remote configuration service from London. It lets teams toggle features per environment, user or segment, change configuration values without releasing new app versions, and run A/B tests through integrations with analytics tools. It offers SDKs for most languages, an edge API for low latency, real-time flag updates, and an MCP server for AI coding tools. Deployment is flexible: the hosted cloud, a dedicated private cloud, or self-hosting the open-source version, with an enterprise licence adding role-based access, audit logs and change requests. The cloud Free plan includes a monthly request allowance, and paid Start-Up and Scale-Up plans raise limits and add seats; enterprise is quoted. It is a good middle ground between LaunchDarkly's polish and pure self-hosted projects, though its experimentation features are lighter than dedicated testing platforms. It runs in the browser, with SDKs for web, mobile and server.

Best for: Teams wanting open-source flags with the option of hosted or on-prem deployment.

What works

Cloud, private cloud or self-hosted deployment
Remote config alongside feature flags
Free hosted plan to start

Why people leave

Governance features need an enterprise licence
Lighter experimentation than dedicated tools

Top Flagsmith alternatives

See all 5

1
Unleash
Another mature open-source flag platform with enterprise governance.
66.5
2
LaunchDarkly
Fully managed flags with release guardrails at scale.
62.6
3
ConfigCat
Hosted flags with unlimited seats and a simple forever-free plan.
59.6
4
GrowthBook
Open-source flags with real experiment analysis built in.
57.2
5
PostHog
Flags bundled with analytics and replay on one platform.
55.3

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Flagsmith: common questions

Is Flagsmith free?

Yes. Flagsmith is free, open-source software that you can host yourself.

Is Flagsmith open source?

Yes. The source code is on GitHub at Flagsmith/flagsmith. You can also run it on your own server.

What platforms does Flagsmith run on?

Flagsmith is available for Web and Self-hosted.

What are the best alternatives to Flagsmith?

The highest-ranked Flagsmith alternatives right now are Unleash, LaunchDarkly and ConfigCat. See the full ranked list for pricing, platforms and verified facts.

See all 5 Flagsmith alternatives

Flagsmith facts

4 of 4 verified

Free plan: Up to 50,000 requests/month; Checked Oct 25, 2026flagsmith.com(opens source in a new tab); “Free plan includes: Up to 50,000 Requests Per Month”
Extra API calls: From $50 per million; Checked Oct 25, 2026flagsmith.com(opens source in a new tab); “Free plan includes: Up to 50,000 Requests Per Month* Additional API calls start at $50 per million per month”
License: BSD-3-Clause; Checked Oct 25, 2026flagsmith.com(opens source in a new tab); “Visit GitHub Read the Docs Trusted by top development teams 1 BSD-3-Clause licence One of the most permissive open-source licences available—no restrictions on commercial use.”
Self-hosting: Yes, documented; Checked Oct 25, 2026docs.flagsmith.com(opens source in a new tab); “Welcome to the Flagsmith deployment and self-hosting guide.”