React Dependency Compatibility Matrix Minimum versions required for React 18.3.1 and React 19 compatibility. Use this skill whenever checking whether a dependency supports a target React version, resolving peer dependency conflicts, deciding whether to upgrade or use legacy peer deps , or assessing the risk of a react router v5 to v6 migration. Review this matrix before running npm install during a React upgrade and before accepting an npm dependency conflict resolution, especially where concurrent mode compatibility may be affected. Core Upgrade Targets Package React 17 (current) React 18.3.1 (min) React 19 (min) Notes react 17.x 18.3.1 19.0.0 Pin exactly to 18.3.1 for the R18 orchestra react dom 17.x 18.3.1 19.0.0 Must match react version exactly Testing Libraries Package React 18 Min React 19 Min Notes @testing library/react 14.0.0 16.0.0 RTL 13 uses ReactDOM.render internally broken in R18 @testing library/jest dom 6.0.0 6.0.0 v5 works but v6 has React 18 matcher updates @testing library/user event 14.0.0 14.0.0 v13 is sync, v14 is async API change required jest 27.x 27.x jest 27+ with jsdom 16+ for React 18 jest environment jsdom 27.x 27.x Must match jest version Apollo Client Package React 18 Min React 19 Min Notes @apollo/client 3.8.0 3.11.0 3.8 adds useSyncExternalStore for concurrent mode graphql 15.x 16.x Apollo 3.8+ peer requires graphql 15 or 16 Read references/apollo details.md for concurrent mode issues and MockedProvider changes. Emotion Package React 18 Min React 19 Min Notes @emotion/react 11.10.0 11.13.0 11.10 adds React 18 concurrent mode support @emotion/styled 11.10.0 11.13.0 Must match @emotion/react version @emotion/cache 11.10.0 11.13.0 If used directly React Router Package React 18 Min React 19 Min Notes react router dom v6.0.0 v6.8.0 v5 → v6 is a breaking migration see details below react router dom v5 5.3.4 (workaround) ❌ Not supported See legacy peer deps note react router v5 → v6 is a SEPARATE migration sprint. Read references/router migration.md . Redux Package React 18 Min React 19 Min Notes react redux 8.0.0 9.0.0 v7 works on R18 legacy root only breaks on concurrent mode redux 4.x 5.x Redux itself is framework agnostic react redux version matters @reduxjs/toolkit 1.9.0 2.0.0 RTK 1.9 tested against React 18 Other Common Packages Package React 18 Min React 19 Min Notes react query / @tanstack/react query 4.0.0 5.0.0 v3 doesn't support concurrent mode react hook form 7.0.0 7.43.0 v6 has concurrent mode issues formik 2.2.9 2.4.0 v2.2.9 patched for React 18 react select 5.0.0 5.8.0 v4 has peer dep conflicts with R18 react datepicker 4.8.0 6.0.0 v4.8+ added React 18 support react dnd 16.0.0 16.0.0 v15 and below have R18 concurrent mode issues prop types any any Standalone unaffected by React version Conflict Resolution Decision Tree legacy peer deps Rules Only use legacy peer deps when: The package has no React 18 compatible release The package is actively maintained (not abandoned) The conflict is only a peer dep declaration mismatch (not actual API incompatibility) Document every legacy peer deps usage in a comment at the top of package.json or in a MIGRATION.md file explaining why it was necessary.

react18-dep-compatibility