2023 Optimizely Full Stack (Legacy) release notes

  • Updated

The following is a cumulative list of enhancements and major bug fixes for Optimizely Full Stack (legacy). Because Optimizely Experimentation releases new features and fixes when they are ready, this list will update regularly. Follow this article to receive notifications when new content is added.

These release notes are for Optimizely Full Stack (Legacy).

For the latest version of Optimizely Full Stack, and the default for new projects since February 2021, see Optimizely Feature Experimentation's release notes.

December 2023

New feature

  • Released automatic SRM detection.
    • Every customer needs to quickly identify problems and protect their experiments from unintended traffic imbalances. Optimizely now automatically runs SRM detection tests embedded within your Stats Engine A/B experiments. When the Optimizely detector finds unusual imbalances in visitor traffic to an experiment's variations, it identifies the severity and then sends out an in-product notification. You can now detect experiment problems early and without manual effort. Read the Optimizely blog post, A smoke alarm for your experiments: Introducing Optimizely’s Automatic sample ratio mismatch Detection, to learn more.

August 2023

New release

Experiment Collaboration is designed to help teams manage their experiment ideation, planning, and hypothesis-creation process more effectively. You can currently link your Optimizely Full Stack (Legacy) experiments to your Hypothesis through your experiment URL. Learn more and create your first hypothesis by following the seven steps to set up Experiment Collaboration.

May 2023


  • The Optimizely Full Stack Experimentation Flutter SDK is in general availability.

Bug Fixes

  • Fixed a bug where Something Went Wrong would appear on the Experiments overview page.
  • Fixed a bug where the percentage completed for project migration from legacy Full Stack to Feature Experimentation would return to 0%.
  • Fixed a bug where you could delete a variation in non-production environments during a running experiment instead of just being able to pause them.
  • Fixed a bug where the Jira integration would not appear in projects.