JSON Formatter & Validator
Pretty-print, minify and validate JSON with syntax highlighting. Parse errors are reported with the exact line and column so you can find the problem straight away.
Recursively orders object keys — handy when diffing two documents that only differ in key order.
0 chars · 0 bytes · 0 lines
Output
0 chars · 0 bytes · 0 lines
What this tool handles
Errors with a location
Browsers only report a character offset. This tool converts it into a line and column number, which is what you actually need in a large document.
Format or minify
Switch between 2 spaces, 4 spaces or tabs for readable output, or strip every byte of whitespace for transport.
Sorted keys for diffing
Optionally sort object keys recursively so two documents that carry the same data compare cleanly line by line.
Frequently asked questions
Does formatting change my data?
No. The document is parsed and re-serialised, so only whitespace and key order change. Values, types and structure stay exactly as they were.
Why is my JSON reported as invalid?
The most common causes are trailing commas, single quotes instead of double quotes, unquoted keys and comments — none of which are valid JSON. The error message points at the line and column.
Can it handle large files?
Yes, within the memory of your browser tab. Formatting happens locally, so there is no upload limit, but multi-hundred-megabyte documents may feel slow.
Is my JSON sent to a server?
No. Parsing and formatting run in your browser, which matters because JSON pasted into these tools often contains API responses, tokens or personal data.