Beautify and validate JSON

A free online JSON formatter — debug a 50 MB API response that returned on a single line, find the unbalanced bracket in a 5000-line config, or minify a JSON blob before shipping it in a build. Paste any JSON, hit Beautify for clean indented output, or Minify to strip whitespace before transport. Validation surfaces the exact line and column of any syntax error so you don't hunt through deeply-nested payloads. Auto-formats as you type. Three indent presets (2 spaces, 4 spaces, Tab) — match jq -c, prettier or your team's style guide. Output matches what JSON.stringify produces, so it round-trips cleanly through any consumer.

How to format JSON

Paste your JSON

Click Paste or paste manually into the left pane.

Pick an indent

2 spaces by default, switch to 4 or Tab if you prefer.

Beautify or Minify

Beautify pretty-prints; Minify strips whitespace.

Copy or download

Copy to clipboard or save as a .json file.

Live validation, accurate error line and column, three indent presets

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Features

Beautify with three indents Minify for transport Pinpoint syntax errors Live auto-format Byte stats + savings Clipboard + download

Common uses

Inspect an API response that returned on a single line.
Find the unbalanced bracket in a 5000-line config file.
Minify a JSON config before shipping it in a build.
Spot the missing comma in a JSON literal someone shared.

Why format here

Most browser tools either run your JSON through a paid backend or wrap the textarea in three layers of ads and trackers. This one formats on every keystroke and shows the actual line+column of syntax errors instead of just "Unexpected token at position 4827". The output matches strict JSON (RFC 8259) so it round-trips cleanly through jq, Postman, Python's json module, or any other consumer.

Frequently asked questions

Free?

Yes — no account, no limits.

Does it support JSON5 / JSONC?

No. This tool validates strict JSON (RFC 8259), so trailing commas, // comments, and unquoted keys are rejected. If your file has JSONC comments (tsconfig.json, VS Code settings), strip them first or use a JSONC-aware parser.

Big files?

Bound by your browser's memory — easily handles 10 MB+. Very large files (200 MB+) may be sluggish because the formatter re-runs on every keystroke. For multi-hundred-MB payloads, jq -r on the command line stays the right tool.

Does the order of keys change?

No. Object key order is preserved in source order — useful when your downstream consumer is order-sensitive (some signed-payload schemes, hash-based caching, deterministic diffs).

Unicode characters?

Preserved as-is. The output uses UTF-8 byte counts in the stats.

Mobile?

Yes. Paste, tap Beautify, copy.

💡 Want us to improve this tool just for you?

We can — and it's free! Just send us a quick message with your idea. If you'd like to discuss it in detail, leave your email and we'll get back to you. You can stay anonymous.

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Who is this tool for?

💻 Developers & IT Pros

Published 22 May 2026 Updated 02 Jun 2026