JSON Formatter and Validator
Paste JSON to pretty-print, minify or validate it, with the exact position of any error.
Everything is parsed in your browser — no JSON is uploaded.
How to use JSON Formatter
- 01Paste your JSON into the input box.
- 02Choose an indent size and press Format, or press Minify to strip all whitespace.
- 03If the JSON is invalid you get the reason and the character position to look at.
About JSON Formatter
Formatting happens entirely in your browser, so API responses, tokens and customer data you paste here never travel over the network.
Most JSON errors come from a short list of causes: a trailing comma after the last item, single quotes instead of double quotes, unescaped quotes inside a string, or a missing closing brace. The error position points at where the parser gave up, which is usually just after the real mistake.
Frequently asked questions
- Is my JSON uploaded anywhere?
- No. Parsing and formatting run locally in your browser.
- Can it handle large files?
- Yes, several megabytes is fine, though very large documents may take a moment to render.
- Why does my JSON fail to validate?
- Most often a trailing comma, single quotes, or a missing bracket. The error message shows the position.
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