JSON Formatter
Format and beautify JSON online for free. Validate and pretty print JSON directly in your browser with no signup.
Your files are processed locally in your browser and are not uploaded to our servers.
How to use JSON Formatter
- 1
Paste your JSON into the box.
- 2
Choose an indentation style — 2 spaces, 4 spaces, or tabs.
- 3
Click "Format." If the JSON is invalid, a specific error message explains what's wrong.
- 4
Copy or download the result.
Common uses
- Pretty-printing a minified API response to actually read it
- Reformatting a config file to a consistent indent style
- Turning a single-line JSON blob into something reviewable in a pull request
Supported formats and limitations
Accepts JSON, up to one file at a time.
- This formats standard JSON only — it doesn't support JSON5, JSONC (comments), or other relaxed variants.
- Very large JSON documents (many megabytes) may take a moment to parse, since the whole document is parsed before it can be reformatted.
Frequently asked questions
No. Parsing and formatting both happen entirely in your browser using the native JSON parser.
You'll see a specific error message describing what's wrong, rather than a silently broken or empty result.
Yes — choose 2 spaces, 4 spaces, or tabs before formatting.
No — only standard JSON, matching what `JSON.parse` accepts. Comments or trailing commas will be reported as invalid.
Yes, 5 MB — comfortably more than typical config files or API responses.