digitpdffile tools · on your device

JSON formatter & validator

Paste messy JSON, get it neat — with a precise error message and line number when it's broken.

Runs on your device No uploads, ever Free, no account

How it works

  1. Paste your JSON

    Or a piece of it — the tool tells you where the syntax breaks, line included.

  2. Format or minify

    Two spaces, four spaces or tabs for readability; one line for feeding to something else.

  3. Copy or download

    Copy button for the clipboard, or take it as a .json file.

Questions people actually ask

What counts as invalid JSON?

Trailing commas, single quotes, unquoted keys, comments — the things that make JSON look like JavaScript but aren't. The error message points at the line and character.

Can it handle large files?

Very large — megabytes of JSON format in well under a second since it's a genuine parser, not a regex trick.