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Optimizely Full Stack is a feature flagging and experimentation platform for websites, mobile apps, chatbots, APIs, smart devices, and anything else with a network connection.

You can deploy code behind feature flags, experiment with A/B tests, and use percentage deliveries to roll out or roll back flags immediately. All of this functionality is available with microsecond performance impact via easy-to-use, open source SDKs.


Create a free Optimizely Rollouts account

Optimizely Rollouts is the free plan for Full Stack, designed for startups and teams looking to get started. It comes with free feature flags and the ability to run one A/B test at a time.

Sign up for a free Rollouts account.

Client-side and server-side SDKs

See the following architectural diagram for an overview of Full Stack's server-side SDKs:


And our client-side SDKs, highlighting our mobile SDKS:


For more detailed diagrams, see Implementation checklist.


Check out the following resources for an overview of Optimizely Full Stack.



Introducing our new beta flags-first experience

7 minute video describing flags and flag rules and how they differ from the older experience of rollouts and feature tests.

Roll out with feature flags

60-second, high-level video

Flappy Bird interactive tutorial

3-minute interactive gameplay tutorial. Click through steps to experiment with features in the game.

5 Powerful Capabilities of Optimizely

4-minute video explaining key features.

Supported functionality

Our SDKs are built for developers, and support:

  • Feature flags and experimentation: Our SDK framework natively integrates feature flags and product experimentation, so you can roll features out, roll them back, and continuously iterate your flags by learning from each release.
  • Remote configuration: Update your app in real time without a code deploy. Toggle flags on and off, and even make changes to your experiments while they're running.
  • Low latency: In-memory bucketing means no blocking network requests. Test in performance-critical code paths, secure environments, and more.
  • Real-time results: Optimizely's Stats Engine provides best-in-class statistical modeling and immediate, trustable results without waiting for long, manual data queries.
  • Cross-platform experimentation: Run server-side or client-side, on any connected device—mobile apps, websites, TV apps—with consistent bucketing across different languages.

Get started

Learn more about major concepts in Full Stack or jump into creating your first experiment:

  1. Use the Quickstarts to install the SDK and instantiate it in your code. If you don't want to install, use the JavaScript (Browser) HTML script quickstart method. Or take a look at the SDK reference guides (optional: customize i.e. configuration polling interval).
  2. Define feature flags that you'll use to roll out feature code gradually, make remote configurations, or run experiments. Choose user IDs, target audiences with attributes, track events, and preview flag variations.
  3. Use your feature flag to run A/B tests without deploying code.
  4. Analyze the results of your experiment.

See the SDK reference guides for details about each API method, such as required arguments, return values, and side effects.

See the Best Practices section for recommendations and considerations when implementing a Full Stack SDK.



To build a company-wide experimentation program, consider pairing Optimizely's server-side experimentation product, Full Stack, with our client-side experimentation product, Optimizely Web. See our knowledge base article: Experiment end-to-end with Optimizely Web and Full Stack.

If you have any questions, please contact support. We are happy to help you set up any of our SDKs!