JSON Formatter & Validator
Format and validate your JSON instantly. Paste your code, get clean readable output in one click. No signup, no install. Free forever.
What is JSON Formatter & Validator?
The JSON Formatter takes raw, minified, or messy JSON and instantly outputs clean, indented, readable code. Paste your JSON and it validates the structure in real time — errors are highlighted so you can pinpoint exactly what's wrong, even in large payloads. Switch between compact and pretty-print modes with a single click.
Developers use a JSON formatter every day — debugging API responses, reading config files, reviewing webhook payloads, or sharing clean data with teammates. The difference between a good and a great JSON tool is speed: no page reload, no copy-pasting into a new tab, no sign-in wall. Just paste and your result appears immediately.
Everything runs in your browser — your data never leaves your device. No account needed, no sign-up, no server upload. Just paste and go.
How to use
Frequently asked questions
Yes. The formatter runs entirely in your browser using JavaScript. Your JSON is never sent to any server and never stored anywhere.
There's no server-side limit. Very large files are constrained only by your device's available memory, which is typically several hundred megabytes.
No. All useTool tools are completely free and require no account or sign-up of any kind.
Yes. Invalid JSON is highlighted with an error message pinpointing the exact location of the problem.
Pretty-print adds indentation and line breaks for human readability. Compact mode removes all whitespace to minimize file size — useful for API payloads.