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JSON Formatter & Validator
Paste messy or minified JSON to beautify it with clean indentation, minify it back down, or validate it with clear error messages. Everything runs in your browser — your data never leaves the page.
Format, validate and minify JSON in your browser
JSON is everywhere — API responses, config files, exports — but it often arrives as one long unreadable line. This JSON formatter re-indents it into a clean, readable structure, highlights the syntax, and tells you immediately if the JSON is invalid and where. Need it compact again? Minify it back to a single line. Nothing you paste is ever uploaded.
What you can do
- Format / beautify — turn minified JSON into readable, indented JSON.
- Minify — strip whitespace to make the smallest possible JSON.
- Validate — instantly see whether your JSON is valid, with the error location if not.
- Choose indentation — 2 spaces, 4 spaces, or tabs.
Frequently asked questions
Is my JSON sent to a server?
No. All formatting and validation happen locally in your browser. Your data is never uploaded, stored, or logged.
Why does it say my JSON is invalid?
Common causes are trailing commas, single quotes instead of double quotes, missing quotes around keys, or an unclosed bracket. The error message points to where parsing failed.
Does it work with large JSON files?
Yes, within your device's memory. Because everything runs locally, big files stay private and there's no upload wait.