JSON Formatter
Format and validate your JSON code instantly
This JSON formatter beautifies messy or minified JSON into readable, indented code, and validates it against the JSON spec so you can spot syntax errors — missing commas, unquoted keys, trailing commas — before they break your application. Everything runs in your browser: your data is never uploaded to a server.
Frequently Asked Questions
Is my JSON data uploaded anywhere?
No. Formatting and validation happen entirely in your browser using client-side JavaScript. Your JSON never leaves your device or gets sent to our servers.
Why does my JSON show a red 'Format Invalid' error?
The validator checks your input against the JSON specification. Common causes are trailing commas after the last item, single quotes instead of double quotes, unquoted keys, or a missing closing bracket. Click Validate to see the exact line and column of the error.
Can I convert JSON to other formats?
Yes — use the converter links above to turn JSON into XML or YAML, or the reverse. Conversions run instantly and preserve nested objects and arrays.
Is there a limit to how large a JSON file I can format?
The formatter runs in-browser using the Monaco editor, so practical limits depend on your device's memory rather than a fixed cap. Very large files (tens of megabytes) may feel slower to scroll and edit.
Can I minify JSON?
Yes — click Minify to remove all whitespace outside strings. Keys, values and key order stay exactly as written, and invalid JSON is reported with its line and column instead. There is a dedicated JSON minifier page at /json-minifier.
Can I see what changed while I was editing?
Yes — click Snapshot to save a checkpoint of your current JSON, then keep editing. A button appears when the content differs from that checkpoint, opening a diff view. The comparison is key-order- and formatting-independent, so reformatting or reordering keys alone won't count as a change.
Have suggestions or feedback? We're constantly improving FormatChamp based on your comments.