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JSON Formatter & Validator

Paste or type JSON below. Format it with proper indentation, minify it for compact storage, or validate its structure — all in real time.

Free Forever
Works Completely In Your Browser
No Upload Required
Privacy Friendly
0Keys
0Lines
0Characters
Idle

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About this tool

The JSON Formatter & Validator is a dual-purpose tool that helps you work with JSON data more efficiently. Paste any JSON string into the input area and instantly see key metrics — the number of keys, lines, and total characters. Use the Format button to pretty-print your JSON with proper indentation for readability, or Minify to collapse it into a compact single line for storage or transmission. If your JSON contains a syntax error, the tool highlights the exact location of the problem so you can fix it quickly. All processing happens in your browser — nothing is uploaded to any server, and no data is retained after you close the tab.

Frequently asked questions

What size JSON can I format?
There is no server-side limit. The tool processes JSON entirely in your browser, so the maximum size depends on your device's memory.
Does it validate JSON syntax?
Yes. Invalid JSON is detected instantly and the error location (line and column) is displayed, helping you find and fix syntax issues quickly.
Can I minify JSON for production use?
Yes. The Minify button collapses formatted JSON into a compact single line, reducing file size for storage or transmission.
Does it support comments in JSON?
No. JSON does not officially support comments. If you need comments, consider using JSONC format or stripping them before validation.
What is the difference between formatting and validating?
Formatting pretty-prints JSON with indentation for readability. Validating checks whether the JSON is syntactically correct. The tool does both automatically.
Can I format JSON from an API response directly?
Yes. Paste any JSON string from an API response, log file, or config file. The tool cleans and formats it with proper indentation instantly.

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