JSON Formatter & Validator

Formatted JSON will appear here...

Why Use This JSON Formatter?

Most online JSON formatters upload your data to a server. This one doesn't. Every format, validation, and minification happens right in your browser — your JSON never leaves your device. That means it's faster, safer, and works offline after the first load.

Features

• Format: Indent and beautify minified JSON with 2-space indentation
• Minify: Compress JSON to a single line for minimal file size
• Validate: Check if your JSON is syntactically correct with line-level error reporting
• Copy: One-click copy formatted output to clipboard
• Privacy: Everything runs in your browser — 0 servers, 0 uploads, 0 logs
• Speed: Instant results — no network round-trip, no waiting for a server

Common JSON Errors & How to Fix Them

Trailing commas

JSON does not allow commas after the last item in an array or object. {"a":1,} is invalid. Remove the final comma.

Unclosed brackets

Every { needs a matching }. Every [ needs ]. Use the formatter to spot mismatches instantly.

Single quotes

JSON requires double quotes for strings. {'key':'value'} won't parse. Replace with double quotes.

Comments in JSON

JSON doesn't support comments. If you need comments, use JSONC (JSON with Comments) or move them outside the data.

Unescaped characters

Backslashes and quotes inside strings must be escaped. "path\to\file" should be "path\\to\\file".

JSON Formatter vs Other Tools

Most JSON formatting tools — including popular ones like jsonformatter.org — process your data on their servers. This means your JSON (which often contains API keys, user data, or business logic) gets sent to a third party. Our tool does everything locally. You can verify this: open DevTools → Network tab, format some JSON, and you'll see zero network requests.

Frequently Asked Questions

Is this JSON formatter really free?

Yes. No registration, no payment, no limits. We support the site through a single non-intrusive ad.

Does it work with large JSON files?

Yes — files up to ~50MB work in most modern browsers. Very large files (>10MB) may take a moment to format. For extremely large JSON, we recommend splitting it into smaller chunks.

Can I use this offline?

Yes! Once the page loads, disconnect your internet — the tool still works perfectly. All processing is local.

Does it preserve JSON structure?

Yes. The formatter preserves all keys, values, arrays, nested objects, and data types. It only changes whitespace and indentation.