JSON Formatter & Validator — Free
Format, validate, and minify JSON. Detects syntax errors and shows exact position. 100% private — nothing leaves your browser.
Format & validate
Pretty-print with 2 or 4 spaces. Syntax errors shown with exact message.
Minify for production
Remove all whitespace and line breaks. See the exact byte reduction percentage.
Fully private
JSON.parse and JSON.stringify run in your browser. No data ever leaves your device.
What is a JSON formatter?
A JSON formatter takes raw, unindented JSON — often a single unreadable line returned by an API — and pretty-prints it with proper indentation, line breaks, and spacing so it's easy to read and debug. Pixvert's JSON formatter also validates the syntax as you go, pointing out exactly where a comma, bracket, or quote is missing.
Working with APIs, config files, or logs almost always means dealing with JSON that's either minified for transport or pasted without formatting into a text editor. This tool instantly reformats it with your choice of 2 or 4-space indentation, making nested objects and arrays visually clear.
The same tool works in reverse: minify formatted JSON down to a single compact line to reduce payload size before sending it over a network or embedding it in code — useful once you're done editing and need production-ready output.
How to format and validate JSON
- 1
Paste your JSON — drop in raw or minified JSON from an API response, file, or config
- 2
Choose indentation — select 2 or 4 spaces for the pretty-printed output
- 3
Check for errors — invalid JSON is flagged immediately, with the location of the syntax problem
- 4
Format or minify — switch between pretty-printed and minified output depending on what you need
- 5
Copy the result — copy the formatted or minified JSON with one click
When to use a JSON formatter
Debugging API responses
Paste a raw API response to instantly see its structure and spot missing or malformed fields.
Reviewing config files
Format a minified config file to understand its structure before editing it.
Validating hand-written JSON
Catch syntax errors like trailing commas or unquoted keys before they break a build or deploy.
Minifying for production
Strip whitespace from formatted JSON to reduce payload size before sending it over an API.
Learning JSON structure
See nested objects and arrays laid out clearly when learning how an API or data format is structured.
Why use Pixvert's JSON formatter?
- ✓100% local processing: your JSON is never sent to a server — everything runs in your browser
- ✓Instant validation: syntax errors are flagged immediately with a clear indication of the problem
- ✓Format or minify: switch between pretty-printed and compact output in one tool
- ✓No signup, no limits: format as much JSON as you need, for free
Frequently Asked Questions
Is my JSON data sent to a server?
No. All formatting, validation, and minification happens locally in your browser using JavaScript. Your data is never transmitted.
What happens if my JSON is invalid?
The tool flags the syntax error and points to roughly where the problem is, such as a missing comma, unclosed bracket, or unquoted key.
Can I format very large JSON files?
Yes, though extremely large files (several megabytes) may take a moment to process depending on your device, since parsing happens in the browser.
What's the difference between formatting and minifying?
Formatting adds indentation and line breaks for readability. Minifying removes all unnecessary whitespace to produce the smallest possible output, typically used before sending data over a network.
Does the tool support JSON5 or JSONC (comments)?
No, the tool validates against strict JSON syntax as defined by the JSON specification, which does not allow comments or trailing commas.
Can I convert JSON to CSV here?
Not on this page, but Pixvert has a dedicated JSON ↔ CSV converter for that.