Open Source Feature Flags

Try open source feature flag management with full transparency and no vendor lock-in

Flagsmith UI
Module UiModule UiModule UiModule UI
Module UI

Try feature flag management on your terms

Get started and see whether Flagsmith works for your needs.

Full transparency. Contribute on GitHub, view the roadmap, and communicate with our team.

Built-in testing and community. Open source feature flags tested and used by global dev teams.

No vendor lock-in. We partner with OpenFeature and our open source version is always available.

View our GitHub

Open source feature flags

Flagsmith makes it easy to create and manage open source feature flags across web, mobile, and server side applications.



Segmentation lets you target flags and releases based on your user base. Run phased rollouts, beta testing, and more.


Integrate with your stack

Integrate Flagsmith with the tools you and your teams already use (e.g. observability, CI/CD, analytics, and so on). Keep your decision points where they are.

Illustration Bag

Our open source licensing and ethos

The vast majority of the platform is open source. View our GitHub.

Most of the platform is under the BSD-3-Clause license. A small number of repositories are under the MIT license.

We built Flagsmith as an open source feature flag tool we needed and couldn't find on GitHub. Core functionality stays open, always.

Use cases for open source feature flags


Decouple deploy and release

Achieve continuous deployment by deploying behind flags, and then only toggling them on when a release is scheduled.


Canary Deployments

Using Flagsmith, you can release new features to a small percentage of your users initially, and then enable them for the rest of your users over time.


A/B/n Testing

Once you’ve integrated the Flagsmith SDK and gated a feature with a flag, you can then easily use that flag to power A/B/n tests.

Enterprise/open source differences

Core feature flag functionality is open source. (Flags, segments, identities, etc.)

Several enterprise-level management features are not open source.

They are source available, however to use them in production we require that you have a valid Flagsmith Enterprise license.

Contact us
Illustration Laptop

The licensing for each repository is clearly shown in GitHub.

Remote config

With Flagsmith’s open source remote config capabilities, you can change or test out different feature properties without deploying new code.

Configure different elements of your features – like the font size of a header or color of a CTA button – directly through Flagsmith and release the changes to users in just a few clicks.

Learn More
Module UiModule UiModule UiModule UI
Module UIFlagsmith UI
Why use open source feature flags?

Open source feature flags let you get started and test the tool on your terms. There's also full transparency with open source, built-in testing by devs around the globe, and the ability to contribute or communicate with our dev team on the Flagsmith GitHub.

Do you accept open source contributions?

Yes! Here are our guidelines for contributing to open source feature flags. If you have any questions about your contribution, you can also chat with us on Discord.

How do you decide what to open source?

Our core functionality stays open. This means you can use open source feature flags and feature management no matter what. Several of our enterprise-level management features are not open source, but they are source available. You can read more about our build decisions here.

What is OpenFeature and how do you work with them?

OpenFeature is an open specification that offers a vendor-agnostic, community-driven API for feature flagging that works with feature flag management tools (like Flagsmith) or in-house solutions. We're proud to partner with OpenFeature and offer OpenFeature providers to prevent vendor lock-in at the code level.

Open source feature flags are used by development teams around the globe

Illustration Mail Box

Contact Us!

We will be in touch with you shortly.
Oops! Something went wrong while submitting the form.