About JSON Formatter & Validator
JSON Formatter & Validator makes nested objects and arrays readable, checks syntax, and produces a compact form when whitespace should be removed.
Formatting is useful for review and debugging; minifying is useful for compact request bodies and fixtures. JSON does not allow comments or trailing commas, so an error often points to a character just before the reported location.
How to use this developer tool
- Paste or upload a JSON value and choose the indentation you want to review.
- Format the document and read the validation message if conversion fails.
- Keep the formatted copy for debugging, or switch to minify when the receiving system expects compact JSON.
Privacy and data handling
JSON is processed in the current browser. Use redacted fixtures for tokens, customer records, and configuration files, even when the page indicates local processing.
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Frequently asked questions
Why is my JSON invalid when it looks almost correct?
Common causes include single quotes, trailing commas, unquoted property names, mismatched brackets, and a syntax error earlier than the reported position.
Does formatting change the data?
It changes whitespace and representation, not the parsed values. Preserve a copy of the original when exact bytes matter.
Should I minify JSON before debugging it?
Usually no. Pretty-printed JSON makes nesting and the location of a problem easier to inspect.