Paste a GST number — instantly check its format & checksum, and read the state, PAN and entity type.
Paste the 15-character GSTIN — it checks the format and the built-in checksum digit and reads out state, PAN and type. A valid checksum means the number is well-formed; it doesn't confirm the business is currently active on the GST portal.
15 chars: 2-digit state code + 10-char PAN + a registration serial + a default "Z" + a checksum character.
Completely free, no login. It runs entirely in your browser.