JSON Formatter
Format, validate and minify JSON with clear error messages.
About this tool
Paste JSON, pick an indent style (2 spaces, 4 spaces or tabs; the choice is remembered) and hit Format. Invalid input gets you the line and column of the first error instead of a vague failure. Minify strips whitespace when you need compact output.
Everything runs in your browser, so the JSON you paste is never uploaded or logged. With no network round-trip, even multi-megabyte payloads format in a blink.
Frequently asked questions
- Is it safe to paste sensitive JSON here?
- Yes. Formatting runs as JavaScript in your browser, so the JSON you paste is never sent to a server. It keeps working even if you disconnect from the internet.
- How large a JSON file can this handle?
- Multi-megabyte payloads format in well under a second since there is no upload. Very large inputs (50MB+) may render slowly in the output box, but parsing is fast.
- What does the error message tell me?
- It reports the line and column of the first syntax error plus the parser message. The culprit is usually a trailing comma or a missing quote.
Related tools
Unix Timestamp Converter 📌 Convert Unix timestamps to dates and back, in seconds or milliseconds. Base64 Encode / Decode 📌 Encode and decode Base64 text or convert files to data URIs. JWT Decoder 📌 Decode JWT header and payload without your token leaving the page. Diff Checker 📌 Compare two texts and highlight changes line by line or word by word.