How to Format JSON
JSON is easy for machines to read and hard for humans the moment it arrives minified on one enormous line. Formatting adds the indentation and line breaks back so structure becomes visible — and validation tells you precisely where a stray comma or missing brace broke the file, down to the line and column.
Paste or drop your JSON
Type it, paste it, or drag a .json file onto the input. Everything stays in your browser.
Pick a mode
Format to beautify, Minify to compact, Repair to auto-fix, or Tree View to explore it visually.
Copy or download
Grab the result with one click. If it was invalid, the error points at the exact spot.
What the Repair Tool Fixes
Most “invalid JSON” is JSON that a human or a JavaScript file wrote by hand. The repairer scans the text in a single string-aware pass, so it never rewrites anything inside your actual string values — only the structure around them.
Trailing commas
The single most common error. A comma before a closing } or ] is legal in JavaScript but not in JSON, and it is removed.
Single and smart quotes
'value' and curly quotes become standard double quotes, the only kind JSON permits.
Comments
// line and /* block */ comments are stripped, since JSON has no comment syntax.
Unquoted keys
In { name: 1 } the key gets quoted to { "name": 1 } as JSON requires.
Python literals
None, True and False become null, true and false so Python dict output parses.
Byte-order marks
An invisible BOM at the start of a file, a frequent and baffling cause of parse failures, is removed.
Frequently Asked Questions
How do I format JSON online for free?
Paste your JSON and switch to Format mode. It is beautified instantly with your chosen indentation. Free, no signup, no limits.
Is my JSON uploaded to a server?
No. All parsing, formatting and repair happen in your browser, which matters for API keys, tokens and internal data.
How do I fix invalid JSON?
Click Auto-Fix, or use Repair mode. It removes trailing commas, converts single quotes, strips comments, quotes bare keys and more, then re-validates.
What does minify do?
It strips every non-essential space and line break, producing the smallest valid JSON. Useful for shrinking API payloads and config files.
Why does it show a line and column for errors?
So you can jump straight to the problem. JSON.parse only gives a character offset, which this tool converts into a line and column.
Can I sort JSON keys alphabetically?
Yes. Enable Sort keys A-Z and every object, at every level, is reordered. Handy for diffing two JSON files.
What is the difference between escape and unescape?
Escape turns raw text into a JSON-safe string with quotes and backslashes encoded. Unescape reverses it, decoding \n, \" and Unicode escapes back to text.
Does the tree view help with large JSON?
Yes. It shows the structure as collapsible nodes so you can drill into a deep object without scrolling through thousands of lines.
Is there a size limit?
Files above 10 MB are rejected because in-browser processing becomes slow. Below that it is effectively instant.
Does it support JSON5 or JSONC?
It reads JSON with comments and trailing commas through the repair tool, but always outputs strict, standard JSON.
Will formatting change my data?
No. Formatting only changes whitespace. Sort keys reorders keys but never alters values. Your data is preserved exactly.
Is this JSON formatter really free?
Completely free, with no accounts, no ads-wall and no premium lock on any feature.
Last updated: July 25, 2026 · FlipMyFormat JSON Formatter & Validator
Written and maintained by the FlipMyFormat team