JavaScript SDK
Javascript-SDK - 6.5.0
Local Holdouts Added support for Local Holdouts, enabling holdout experiments to be scoped to specific feature flag rules rather than applied globally. Local Holdouts let you measure the true incremental impact of individual features by holding out a subset of users from specific rollouts while still serving them other experiences.
Javascript-SDK - 6.4.0
Feature Rollout Added support for Feature Rollouts, a new experiment type combining Targeted Delivery simplicity with A/B test measurement capabilities. Feature Rollouts enable progressive rollouts with full impact analytics, metric tracking, and confidence intervals.
Javascript-SDK - 6.3.1
\#631---january-26-2026 \#changed Updated event retry default config Adjusted default retry configuration for event processing ( #1131 https //github. com/optimizely/javascript-sdk/pull/1131 ) \#bug-fixes Fix UNSTABLE conditionEvaluators option pass custom condition evaluators to decision service ( #1133 https //github.
Javascript-SDK - 6.3.0
\#630---november-19-2025 \#new-features Added Holdouts support Holdouts Feature Experimentation feature is now officially supported. Added configurable prediction endpoint Added ability to configure custom prediction endpoint for CMAB ( #1102 https //github.
Javascript-SDK - 6.2.0
\#620---october-23-2025 \#new-features Added support for Contextual Multi-Armed Bandit (CMAB) Added support for CMAB experiments(Contextual Bandits rules) with new configuration options and cache control. To get decision from CMAB rules, decideAsync and related methods must be used.
Javascript-SDK - 6.1.0
\#610---september-8-2025 \#new-features Added multi-region support for logx events ( #1072 https //github. com/optimizely/javascript-sdk/pull/1072 ) \#performance-improvements Improved performance of variations parsing from datafile ( #1080 https //github.
Javascript-SDK - 6.0.0
\#600---may-29-2025 \#breaking-changes Modularized SDK architecture The monolithic createInstance call has been split into multiple factory functions for greater flexibility and control. Core functionalities (project configuration, event processing, ODP, VUID, logging, and error handling) are now configured through dedicated components created via factory functions, giving you greater flexibility and control in enabling/disabling certain components and allowing optimizing the bundle size for frontend projects.
Javascript-SDK - 5.3.5
\#535---jan-29-2025 \#bug-fixes Rollout experiment key exclusion from activate method( #949 https //github. com/optimizely/javascript-sdk/pull/949 ) Using optimizely.
Javascript-SDK - 5.3.4
\#534---jun-28-2024 \#changed crypto and text encoder polyfill addition for React native ( #936 https //github. com/optimizely/javascript-sdk/pull/936 ) https //github.
Javascript-SDK - 5.3.3
\#533---june-06-2024 \#changed queueMicroTask fallback addition for embedded environments / unsupported platforms ( #933 https //github. com/optimizely/javascript-sdk/pull/933 ) https //github.
Javascript-SDK - 5.3.2
\#532---may-20-2024 \#changed Added public facing API for ODP integration information ( #930 https //github. com/optimizely/javascript-sdk/pull/930 ) https //github.
Javascript-SDK - 5.3.0
\#530---april-8-2024 \#changed Refactor ODP corrections #920 https //github. com/optimizely/javascript-sdk/pull/920 including ODPManager should not be running and scheduling timer if ODP is not integrated to the project (which causes memory leak if one sdk instance is created per request) CreateUserContext should work even when called before the datafile is downloaded and should send the identify ODP events after datafile download completes Other automatic odp events (vuid registration, client initialized) should also be sent after datafile is available and should not be dropped if batching is disabled.
Javascript-SDK - 5.2.1
\#521---march-25-2024 \#bug-fixes Fix empty segments collection is valid ( #916 https //github. com/optimizely/javascript-sdk/pull/916 ) Update vulnerable dependencies ( #918 https //github.
Javascript-SDK - 5.2.0
\#520---march-18-2024 \#new-features Add persistentCacheProvider option to createInstance to allow providing custom persistent cache implementation in react native ( #914 https //github. com/optimizely/javascript-sdk/pull/914 ) https //github.
Javascript-SDK - 5.1.0
\#510---march-1-2024 \#new-features Add explicit entry points for node, browser and react native, allowing imports like import optimizelySdk from '@optimizely/optimizely-sdk/node' , import optimizelySdk from '@optimizely/optimizely-sdk/browser' , import optimizelySdk from '@optimizely/optimizely-sdk/react native' ( #905 https //github. com/optimizely/javascript-sdk/pull/905 ) \#changed Log an error in DatafileManager when datafile fetch fails ( #904 https //github.
Javascript-SDK - 5.0.1
Improved conditional ODP instantiation when odpOptions. disabled true is used ( #902 https //github.
Javascript-SDK - 4.10.0
Add support for configurable closing event dispatcher, and dispatching events using sendBeacon in the browser on instance close ( #876 https //github. com/optimizely/javascript-sdk/pull/876 , #874 https //github.
Javascript-SDK - 4.9.4
Improve OptimizelyConfig class instantiation performance from O(n^2) to O(n) where n = number of feature flags ( #829 https //github. com/optimizely/javascript-sdk/pull/829 ) https //github.
Javascript-SDK - 4.9.2
Add package. json script for running Karma tests locally using Chrome ( #651 https //github.
Javascript-SDK - 4.9.1
January 18, 2022 \- Fixed typescript compilation issue introduced by `4. 9.
Javascript-SDK - 4.9.0
January 14, 2022 Add a set of new APIs for overriding and managing user-level flag, experiment and delivery rule decisions. These methods can be used for QA and automated testing purposes.
Javascript-SDK - 4.8.0
November 29, 2021 \- Added a Lite bundle which does not include Data file manager and Event Processor packages. This reduces the bundle size up to 20% and is helpful for some platforms (such as edge service providers) that do not need extended functionality offered by these packages.
Javascript-SDK - 4.8.0-beta.2
November 1, 2021 \- Removed Client engine validation in the SDK to allow tracking events from new clients without modifying SDK code. https //github.
Javascript-SDK - 4.8.0-beta
October 18, 2021 \- Added a Lite bundle which does not include Data file manager and Event Processor packages. This reduces the bundle size up to 20% and is helpful for some platforms (such as edge service providers) that do not need extended functionality offered by these packages.
Javascript-SDK - 4.6.2
July 15, 2021 \- Fixed incorrect impression event payload in projects containing multiple flags with duplicate key rules (\[#690]\( https //github. com/optimizely/javascript-sdk/pull/690 https //github.
Javascript-SDK - 4.6.1
July 8, 2021 \- Bumped `event-processor` packages to version `0. 8.
Javascript-SDK - 4.6.0
May 27, 2021 \- Added support for multiple concurrent prioritized experiments per flag (\[#664]\( https //github. com/optimizely/javascript-sdk/pull/664 https //github.
Javascript-SDK - 4.5.1
March 2, 2021 \- Refactored TypeScript type definitions to have `OptimizelyUserContext` and `OptimizelyDecision` imported from `shared types` to provide isolation from internal modules (\[#655]\( https //github. com/optimizely/javascript-sdk/pull/655 https //github.
Javascript-SDK - [3.0.1] - February 21, 2019
\### Changed \- Expose default `loggers`, `errorHandlers`, `eventDispatcher` and `enums` on top level require. \- `createLogger` and `createNoOpLogger` are available as methods on `optimizelySdk.
Javascript-SDK - 3.0.0-rc
This is the release candidate version of the 3. 0 SDK \### New Features \- Support for boolean combinations of audiences on experiments (\[#175]\( https //github.
Javascript-SDK - 3.0.0-alpha
This is the alpha release of the 3. 0 SDK, which includes a number of improvements to audience targeting \### New Features \- Support for number-valued and boolean-valued attributes (\[#174]\( https //github.
Javascript-SDK - 2.1.2
https //github. com/optimizely/javascript-sdk/releases/tag/v2.
Javascript-SDK - 2.0.5
https //github. com/optimizely/javascript-sdk/releases/tag/v2.
Javascript-SDK - 2.1.1
https //github. com/optimizely/javascript-sdk/releases/tag/v2.
Javascript-SDK - 2.0.4
https //github. com/optimizely/javascript-sdk/releases/tag/v2.
Javascript-SDK - 2.1.0
Introduces support for bot filtering. (\[#99]\( https //github.
Javascript-SDK - 2.0.1
April 16th, 2018 Improve browser entry point by pointing to the browser index file instead of the webpack-compiled bundle. (\[@DullReferenceException]\( https //github.
Javascript-SDK - 2.0.0
April 11th, 2018 This major release of the Optimizely SDK introduces APIs for Feature Management. It also introduces some breaking changes listed below.
Javascript-SDK - 2.0.0-beta1
March 29th, 2018 This major release of the Optimizely SDK introduces APIs for Feature Management. It also introduces some breaking changes listed below.
Javascript-SDK - 1.4.3
Default skipJSONValidation to true Bump optimizely-server-sdk to version 1. 3.
Javascript-SDK - 1.4.1
Switched to karma/browserstack for cross-browser testing Removed es6-promise Bump optimizely-server-sdk to version 1. 3.
Javascript-SDK - 1.1.0
\- Add global variable name export for use in non-CommonJS environments \- Remove redundant lodash core dependency to reduce bundle bloat https //github. com/optimizely/javascript-sdk/releases/tag/v1.
Javascript-SDK - 1.0.0
\- Introduce support for Full Stack projects in Optimizely X with no breaking changes from previous version. \- Introduce more graceful exception handling in instantiation and core methods.
Javascript-SDK - 0.1.3
\- Add environment detection to event builder so it can distinguish between events sent from node or the browser. https //github.
Javascript-SDK - 0.1.4
\- Add functionality for New Optimizely endpoint. https //github.
Javascript-SDK - 0.1.2
\- Added missing param to tell log endpoint we are sending a CORS request https //github. com/optimizely/javascript-sdk/releases/tag/v0.
Javascript-SDK - 0.1.1
\- Remove percentageIncluded field from JSON schema, which is not needed. https //github.
Javascript-SDK - 0.1.0
\- Beta release of the Javascript SDK for our Optimizely testing solution https //github. com/optimizely/javascript-sdk/releases/tag/v0.