Tailwind v3 vs. v4 and migration awareness
Tailwind v3 and v4 differ in setup, configuration conventions, CSS entry points, browser requirements, and some migration details. A code sample containing utility classes may look familiar across versions, while installation or theme instructions may not be portable.
When upgrading, read the official upgrade guide, confirm framework and browser support, review custom plugins and configuration, and compare generated CSS. Avoid making several unrelated changes during the migration; isolate setup changes from visual refactoring so regressions are easier to locate.
Upgrade checklist
Setup:
Use the matching integrationUpdate the build plugin and CSS entry point.
Theme:
Review tokens and configTranslate custom theme settings deliberately.
Sources:
Check file discoveryEnsure application and component files are scanned.
Regression:
Test key screensCompare responsive and interaction states.
Do not mix version instructions
A v3 configuration example may not be the right starting point for a v4 project. Identify the installed version before changing setup.