Format, minify and validate JSON in your browser, with the parser’s own error message when the input is invalid.
Paste JSON, then format or minify.
Your file is never sent to a server. It is read and processed by your own browser, and the results are not stored.
JSON is a data interchange format with a precise grammar. Pretty-printing it should produce exactly the object that input describes; anything else risks silently changing the data. This tool uses the browser’s own JSON.parse, so the rules are the same the browser uses everywhere else.
The output is canonical: two-space or four-space indentation and no extra whitespace beyond that.
The message comes straight from the engine. On modern V8 it includes a snippet of the offending input, which is usually enough to spot the stray comma, unquoted key or smart quote. Some engines also report a character position, which this tool converts to line and column.
If the input is valid JSON but you want something else from it, this is the wrong tool. It formats the structure you gave it, no more.
No. JSON Formatter & Validator runs in your browser, and the file is read there rather than sent to a server for processing. Our host still sees ordinary page-request metadata, which is described on the privacy page.
Yes, JSON Formatter & Validator is free, with no paid tier, no account, and no watermark added to your output. The limits are technical rather than commercial: file size, page count and supported formats are listed on this page.
JSON Formatter & Validator supports .json, .txt files up to 5MB directly in your browser.
The tool does not guess, repair or silently rewrite it. It shows the parser’s own error message, with line and column when the engine reports a position, or the raw message otherwise.
No. The text you paste is parsed in this tab. There is no server request in this tool.
The tool uses the strict JSON grammar. Comments and trailing commas are valid in JSONC and JSON5, not in JSON. If you need those, say so explicitly and use a JSONC-aware editor.