⚡ 100% in-browser · No uploads · No limits

JSON Formatter

Format, validate, minify & explore JSON. 100% private, in-browser.

🔒 Your JSON is parsed in your browser — never sent to a server

Input

Output

Format JSON without sending it anywhere

Many online JSON formatters POST your data to their server to process it — a real problem when that JSON contains API keys, tokens, or customer records. This tool parses and formats entirely in your browser, so sensitive payloads never leave your machine. It also gives you precise error locations, a collapsible tree view, key sorting and minification.

🔒

Truly private

Safe for production payloads — nothing is uploaded, logged, or stored.

🎯

Pinpoint errors

Invalid JSON? Get the exact line and column of the problem, not a vague message.

🌳

Tree explorer

Collapse and expand nested objects and arrays to understand structure fast.

🔤

Sort & minify

Alphabetize keys for clean diffs, or minify to the smallest possible size.

Common uses

Debug API responses — pretty-print a minified response to read it easily.
Validate config files — catch a trailing comma or missing bracket instantly.
Clean up for commits — sort keys so JSON diffs stay small and readable.
Shrink payloads — minify before sending over the wire.

Frequently asked questions

Is my JSON sent to a server?

No. All parsing and formatting happens locally in your browser using the native JSON engine.

How big a file can it handle?

Very large ones — it's limited only by your browser's memory, not an upload cap.

Why does it show a line and column for errors?

We translate the parser's character position into a line/column so you can jump straight to the issue.