Tailwind v4 Upgrade guide — check v4 upgrade blockers in your files
Finds Tailwind CSS v3 syntax that v4 removed or silently redefined - @tailwind directives, bg-opacity-*, outline-none, bare border and ring - with the v4 replacement and a line number. Runs entirely in your browser — nothing is uploaded.
Free here: Scan the file you have open and list every v3 construct v4 removed or silently redefined, with the line number and the v4 replacement. In the editor: Scan every file in the workspace in one command and write a dated Markdown migration report with a per-file count you can hand to your team — that part asks for a licence key.
Same engine as the VS Code extension, byte for byte.