JSON Formatter & Validator
Paste JSON into the editor below — actions transform it in place. Errors are reported with exact line and column positions.
What this tool does
Format pretty-prints your JSON in place with your preferred indentation.
Minify strips all whitespace to reduce payload size.
Validate checks the syntax and reports the exact line and column of the first error —
the same messages your browser's JSON.parse produces, plus position mapping.
Every action keeps the previous content one Undo away.
FAQ
What do Escape / Unescape do?
Escape adds escapes on top of the current content — double quotes become \" and backslashes become \\, while the line structure and indentation stay visible. Unescape reverses it, and also accepts strict single-line string literals with \n sequences. Both work in place — Undo restores the previous content.
What do Unicode → Text / Text → Unicode do?
Unicode → Text decodes \uXXXX escape sequences (including surrogate pairs for emoji) into readable characters. Text → Unicode encodes every non-ASCII character — e.g. Chinese — into \uXXXX escapes so payloads survive ASCII-only channels.
Is my JSON sent to a server?
No. All parsing happens locally with the browser's native JSON parser. Nothing is uploaded, logged or stored.
What is the maximum size?
There is no artificial limit — it depends on your device's memory. Multi-megabyte JSON typically formats in well under a second.
Does it support JSON5 or comments?
Standard JSON only. Remove comments and trailing commas first, or use a JSON5 tool for those dialects.
JSON Formatter & Validator — FAQ
Is JSON Formatter & Validator free to use?
Yes. It is completely free, with no signup, no installation and no usage limits.
Is my data uploaded to a server?
No. The tool runs entirely in your browser — the data you paste or upload never leaves your device.
Does it work on mobile devices?
Yes. It works in any modern desktop or mobile browser, with nothing to install.