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ToolMint

JSON Formatter

Popular

Pretty-print or minify JSON with instant validation. Copy or download the result. Perfect for debugging APIs.

Last updated June 2025 3 min read Works in browser Privacy first

JSON Formatter

Beautify, minify, explore, search and sort any JSON — in your browser.

{
  "name": "ToolMint",
  "tools": 22,
  "free": true,
  "tags": [
    "seo",
    "developer",
    "utilities"
  ],
  "latest": {
    "slug": "meta-tag-generator",
    "released": "2025-06-01"
  }
}
Guide

What this tool is for

JSON is the lingua franca of web APIs. But a minified response from a server is nearly impossible to eyeball. Pasting it here gives you a well-indented, validated version in one click.

Runs entirely in your browser

We never send your JSON to a server. Parsing and formatting happen in-page.

Beautify vs Minify

Action Use it when…
Beautify You’re reading, debugging or reviewing a response.
Minify You’re embedding JSON inline (HTML data attribute, script tag).
Validate You just want a yes/no answer with the error location.

The three most common JSON mistakes

  1. Trailing commas. Valid in JavaScript, invalid in JSON.
    {
  "name": "Toolmint",
  "free": true,
}
  2. Single-quoted keys or strings. JSON requires "double quotes" everywhere.
  3. Comments. JSON does not support // comments or /* ... */. Use JSONC / JSON5 tooling if you need them.
Don’t paste secrets

Anything you paste stays in your browser tab — but treat it like clipboard hygiene: clear the field after use if the JSON contained tokens.

Pro tips

  • Pretty-printed JSON with 2-space indent is the industry norm.
  • When diffing responses, minify first — diffs stay stable across whitespace changes.
  • For very large payloads, use the Download button to save formatted.json instead of scrolling.
Steps

How to use

  1. Paste your JSON on the left.
  2. Click Beautify or Minify.
  3. Copy or download the output.
Why you’ll love it

Benefits

Free forever

No trials, no paywalls, no ads inside the tool.

Zero friction

No sign up, no email, no cookies you didn’t ask for.

Fast by design

Interactions render in under 200ms on modern devices.

In practice

Examples

  • Format a messy API response for debugging.
  • Minify JSON for smaller file sizes.
Tips

Pro tips

  • Wrap JSON in a code editor with syntax highlighting for teams.
  • Keys should be double-quoted — the validator catches single-quoted keys.
Watch out

Common mistakes to avoid

  • Pasting JSON with trailing commas — not valid.
  • Comments in JSON are not standard — use JSONC / JSON5 tooling.

Frequently asked questions

Made with care by ToolMint