JSON Formatter

Key takeaways

• Pretty-print and minify in one workspace
• Runs client-side — data stays on your device
• Highlights invalid JSON with line/column when available
• Supports upload, copy, and download

What is a JSON formatter?

A JSON formatter takes raw JSON text and rewrites it with consistent indentation (pretty-print) or removes whitespace (minify).

Developers use formatters to read API responses, clean config files, and prepare compact payloads for transport. This tool also surfaces parse errors with line and column when the input is invalid.

Features

• Pretty print

  Indent nested objects and arrays with consistent spacing for readability.

• Minify

  Collapse JSON into a compact single-line string for transport or storage.

• Auto format

  Valid JSON is pretty-printed automatically as you type or paste.

• Error highlighting

  Invalid JSON shows line and column so you can fix issues quickly.

• Copy & download

  Copy formatted output to the clipboard or download a .json file.

• Upload support

  Drop a JSON file or browse from disk — processed only on your device.

How it works

1. 1

   Paste or upload JSON

   Drop a .json file or paste raw JSON into the input panel.

2. 2

   Auto-format or run actions

   Valid JSON pretty-prints automatically. Use Minify, Copy, or Download as needed.

3. 3

   Fix errors inline

   Invalid JSON shows the line and column so you can correct it quickly.

Example walkthroughs

• Nested object

  A compact user object becomes readable with indented properties and array items.

  {"user":{"id":1,"name":"Ada","roles":["admin","editor"]},"active":true}

• Array of records

  Inventory-style arrays format cleanly so each record is easy to scan.

  [{"sku":"A-100","qty":3},{"sku":"B-200","qty":1},{"sku":"C-300","qty":8}]

Use cases

• Debug API responses

  Paste responses from curl, Postman, or browser Network tabs to inspect nested fields.

• Clean config before commit

  Normalize package manifests, theme tokens, or feature flags before sharing.

• Prepare payloads for docs

  Pretty-print samples for README files, tickets, and design reviews.

Code snippets

• Pretty-print in JavaScript

  js

  Same idea as Pretty print in this tool — parse then stringify with spacing.

  const pretty = JSON.stringify(JSON.parse(raw), null, 2);

• Minify for transport

  js

  Omitting the space argument collapses whitespace like Minify.

  const compact = JSON.stringify(JSON.parse(raw));

Common errors

• Unexpected token / trailing comma

  Cause: JSON does not allow trailing commas after the last property or array item.

  Fix: Remove the extra comma, or convert from a JS object literal first.

• Single-quoted strings rejected

  Cause: JSON requires double quotes for keys and string values.

  Fix: Replace '…' with "…" before formatting.

About JSON Formatter

JSON Formatter helps you beautify messy API payloads, config files, and logs into readable, indented JSON — or compress them into a single minified line for transport. Reach for it when Network-tab responses, webhook bodies, or theme tokens are hard to scan as one long string.

Pretty-print keeps nested objects and arrays aligned so reviews and tickets stay legible. Minify strips insignificant whitespace when you need a compact body for curl, message queues, or size-sensitive storage. Auto-format runs as you paste valid JSON so the happy path stays zero-friction.

Everything runs locally in your browser. Tokens, customer records, and internal payloads never leave the device — a practical default when you cannot paste production data into hosted “formatters.” Upload and download stay on-device as well.

Best practice: validate structure first if you are unsure the input is JSON, then format. Prefer this tool for whole documents; use JSON Escape only when you need a single string literal. Trailing commas and single quotes fail for a reason — fix the source rather than hoping a formatter “repairs” invalid JavaScript object literals.

Frequently asked questions

Explore more

• All developer tools

  Browse formatters, converters, encoders, and more.

• JSON tools category

  Format, validate, view, compare, diff, and escape JSON.

• Privacy

  How client-side tools handle your data.