JSON Formatter
Format, validate and minify JSON. Runs entirely in your browser. No account, no upload, no limit.
Why this one runs locally
Most "JSON formatter" sites post your payload to a server, which is a problem the moment the JSON contains an API response with tokens or customer records. This one parses in the page with JSON.parse. Open dev tools and watch the network tab — nothing is sent.
Reading the error message
A JSON parse error tells you the character position, not the line. Paste the minified string into the formatter and it will still refuse; instead, look at the character offset and count forward. The three most common causes are a trailing comma, a single-quoted string, and an unquoted key.
When to minify
Minify before an API request or when embedding into a URL parameter; format before reading it. Minifying removes whitespace only, so it never changes the data.