React 19

Libraries that assume React 17 or 18 create compatibility issues during React 19 migration. Dependencies often present larger migration barriers than React itself, requiring teams to audit the entire dependency tree before upgrading.

Automated codemods recommended for React 19 migrations cause regressions or incomplete changes in large codebases. Migration tools are useful but unreliable, requiring teams to treat them as helpers rather than one-click solutions and manually verify changes.