REACT-19.3.0 release notes and known issues

Summary

Below is a list of all new features, APIs, and bug fixes. Read the React 19.3 release post for more information. New React Features <ViewTransition /> : Adds <ViewTransition /> and addTransitionType APIs to power View Transition animations in React ( @sebmarkbage , @jackpope , @gaearon : #31975 , #31987 , #31996 , #31999 , #32001 , #32002 , #32028 , #32029 , #32031 , #32034 , #32038 , #32041 , #32050 , #32090 , #32105 , #32254 , #32379 , #32422 , #32462 , #32540 , #32545 , #32585 , #32599 , #32611 , #32612 , #32617 , #32651 , #32653 , #32656 , #32664 , #32699 , #32723 , #32734 , #32751 , #32752 , #32760 , #32761 , #32764 , #32772 , #32790 , #32819 , #32820 , #32822 , #32833 , #32849 , #33094 , #33191 , #33200 , #33206 , #33293 , #33330 , #33331 , #33332 , #33357 , #33362 , #33433 , #33576 , #34374 , #34450 , #34481 , #34500 , #34502 , #34510 , #34511 , #34539 , #35567 , #35564 , #35485 , #35380 , #35063 , #35060 , #34676 , #36917 , #35337 , #35520 ) Fragment Refs: Add Refs to <Fragment /> to support composable platform behavior ( @jackpope , @sebmarkbage , @eps1lon , @Dhakshin2007 , @chirokas , @teamleaderleo , @fallintoplace : #32465 , #32613 , #32619 , #32654 , #32660 , #32682 , #32722 , #32813 , #32814 , #33056 , #33058 , #33093 , #34069 , #34103 , #34544 , #34545 , #37062 , #37061 , #37060 , #36047 , #36010 , #35642 , #35641 , #35637 , #35630 , #34935 , #37457 , #37408 , #37326 , #37251 , #37171 , #37169 , #37168 , #37167 , #37166 , #37165 , #37164 , #37163 , #37162 , #37161 , #37160 , #37125 , #37063 ) New React DOM Features browser() : a new react-dom API that returns a usable which errors during server rendering and resolves in the browser. use(browser()) inside a <Suspense> boundary marks a subtree as browser-only without reporting a recoverable error ( @gnoff : #37143 , #37241 ) Added an onBrowserBailout option to the react-dom/server APIs to observe when a subtree defers to the browser ( @gnoff #37193 ) Notable changes Enable Trusted Types API integration ( @rickhanlonii #35816 ) Transitions now render independently instead of being entangled into a single render, so a slow transition no longer holds up unrelated ones ( @acdlite #37290 ) Added a DEV-only warning when a component appears to have been unblocked by calling use() conditionally ( @hoxyq , @eps1lon : #37104 , #37203 , #37491 ) All Changes React Fast Refresh Fixes Fix Fast Refresh to find and remount edits to components wrapped behind lazy() ( @sophiebits #36965 ) Fix Fast Refresh so edits to a memo() comparison function take effect ( @sophiebits #36964 ) Fix Fast Refresh crash when an edit changes the kind of a component's type ( @sophiebits #36963 ) Unify hot reload type resolution for Fast Refresh ( @sophiebits #36962 ) Fix Fast Refresh to remount correctly when an edit changes the component kind ( @sophiebits #36950 ) Double invoke effects in StrictMode after Fast Refresh ( @eps1lon #35962 ) Performance Track Fixes Prevent crash when accessing $$typeof in Performance Tracks ( @eps1lon #35679 ) Handle non-string function names in Performance Tracks ( @eps1lon #35659 ) Use minus ( - ) instead of en dash for removed props in Performance Tracks ( @eps1lon #35649 ) Handle arrays with bigints in deep objects in Performance Tracks ( @eps1lon #35648 ) Don't enumerate typed array props in Performance Tracks in DEV ( @UditDewan #36913 ) Bail out of diffing wide objects and arrays in Performance Tracks ( @eps1lon #34742 ) Clear potentially large performance measures in DEV ( @hoxyq #34803 ) Fix missing else branch for renders with no props change in Performance Tracks ( @hoxyq #34837 ) Activity Fixes Fix useSyncExternalStore missing store mutations that happened while an Activity tree was hidden ( @sophiebits #36947 ) Hide portal contents when an Activity is hidden ( @acdlite #35091 ) Prevent metadata hoisting in hidden <Activity> trees ( @ronnakamoto #34983 ) Prevent errors thrown inside a hidden Activity from escaping to the visible UI ( @acdlite #35074 ) Don't

Improvements and security content

• Below is a list of all new features, APIs, and bug fixes. Read the React 19.3 release post for more information. New React Features <ViewTransition /> : Adds <ViewTransition /> and addTransitionType APIs to power View Transition animations in React ( @sebmarkbage , @jackpope , @gaearon : #31975 , #31987 , #31996 , #31999 , #32001 , #32002 , #32028 , #32029 , #32031 , #32034 , #32038 , #32041 , #32050 , #32090 , #32105 , #32254 , #32379 , #32422 , #32462 , #32540 , #32545 , #32585 , #32599 , #32611 , #32612 , #32617 , #32651 , #32653 , #32656 , #32664 , #32699 , #32723 , #32734 , #32751 , #32752 , #32760 , #32761 , #32764 , #32772 , #32790 , #32819 , #32820 , #32822 , #32833 , #32849 , #33094 , #33191 , #33200 , #33206 , #33293 , #33330 , #33331 , #33332 , #33357 , #33362 , #33433 , #33576 , #34374 , #34450 , #34481 , #34500 , #34502 , #34510 , #34511 , #34539 , #35567 , #35564 , #35485 , #35380 , #35063 , #35060 , #34676 , #36917 , #35337 , #35520 ) Fragment Refs: Add Refs to <Fragment /> to support composable platform behavior ( @jackpope , @sebmarkbage , @eps1lon , @Dhakshin2007 , @chirokas , @teamleaderleo , @fallintoplace : #32465 , #32613 , #32619 , #32654 , #32660 , #32682 , #32722 , #32813 , #32814 , #33056 , #33058 , #33093 , #34069 , #34103 , #34544 , #34545 , #37062 , #37061 , #37060 , #36047 , #36010 , #35642 , #35641 , #35637 , #35630 , #34935 , #37457 , #37408 , #37326 , #37251 , #37171 , #37169 , #37168 , #37167 , #37166 , #37165 , #37164 , #37163 , #37162 , #37161 , #37160 , #37125 , #37063 ) New React DOM Features browser() : a new react-dom API that returns a usable which errors during server rendering and resolves in the browser. use(browser()) inside a <Suspense> boundary marks a subtree as browser-only without reporting a recoverable error ( @gnoff : #37143 , #37241 ) Added an onBrowserBailout option to the react-dom/server APIs to observe when a subtree defers to the browser ( @gnoff #37193 ) Notable changes Enable Trusted Types API integration ( @rickhanlonii #35816 ) Transitions now render independently instead of being entangled into a single render, so a slow transition no longer holds up unrelated ones ( @acdlite #37290 ) Added a DEV-only warning when a component appears to have been unblocked by calling use() conditionally ( @hoxyq , @eps1lon : #37104 , #37203 , #37491 ) All Changes React Fast Refresh Fixes Fix Fast Refresh to find and remount edits to components wrapped behind lazy() ( @sophiebits #36965 ) Fix Fast Refresh so edits to a memo() comparison function take effect ( @sophiebits #36964 ) Fix Fast Refresh crash when an edit changes the kind of a component's type ( @sophiebits #36963 ) Unify hot reload type resolution for Fast Refresh ( @sophiebits #36962 ) Fix Fast Refresh to remount correctly when an edit changes the component kind ( @sophiebits #36950 ) Double invoke effects in StrictMode after Fast Refresh ( @eps1lon #35962 ) Performance Track Fixes Prevent crash when accessing $$typeof in Performance Tracks ( @eps1lon #35679 ) Handle non-string function names in Performance Tracks ( @eps1lon #35659 ) Use minus ( - ) instead of en dash for removed props in Performance Tracks ( @eps1lon #35649 ) Handle arrays with bigints in deep objects in Performance Tracks ( @eps1lon #35648 ) Don't enumerate typed array props in Performance Tracks in DEV ( @UditDewan #36913 ) Bail out of diffing wide objects and arrays in Performance Tracks ( @eps1lon #34742 ) Clear potentially large performance measures in DEV ( @hoxyq #34803 ) Fix missing else branch for renders with no props change in Performance Tracks ( @hoxyq #34837 ) Activity Fixes Fix useSyncExternalStore missing store mutations that happened while an Activity tree was hidden ( @sophiebits #36947 ) Hide portal contents when an Activity is hidden ( @acdlite #35091 ) Prevent metadata hoisting in hidden <Activity> trees ( @ronnakamoto #34983 ) Prevent errors thrown inside a hidden Activity from escaping to the visible UI ( @acdlite #35074 ) Don't

Affected products and versions

Recommended action

Review the official publisher document before deployment.

Official publisher evidence