JSON Formatter & Validator

Format (beautify) adds indentation and line breaks so JSON is easy to read. Minify strips all unnecessary whitespace to produce the smallest valid JSON, which is ideal for transport or storage.

There is no hard limit, but because everything runs in your browser, very large inputs (roughly over 5MB) may briefly freeze the tab while processing. For huge files a desktop tool is a better fit.

Once the page has loaded, formatting works without a network connection because the logic runs locally in your browser.

Tree View renders your JSON as a collapsible hierarchy so you can expand and explore nested objects and arrays instead of scrolling through raw text.

Yes. Pick XML, CSV or YAML above the output to convert the JSON you pasted. The indent and sort-keys options apply, and Download saves the result with the matching file extension. CSV needs an array of objects (or a single object); each key becomes a column.

Yes. Every tool on DevUtilsNow is free to use with no account and no limits.

Switch to Repair and most mistakes are fixed for you, with a list of every change. For anything it can't fix, the validator points to the line and column of the error. Our Common JSON Errors guide explains each error message.

Yes. Formatter, beautifier, prettifier and pretty printer all mean the same thing: adding line breaks and indentation so nested objects and arrays are easy to read. This tool also validates the JSON while it formats it, and can minify it back to one line.

Comments, trailing or missing commas, single and curly quotes, unquoted keys, Python and JavaScript values like True, None, undefined and NaN, numbers like +1, .5 or 007, raw line breaks in strings, Markdown code fences and JSONP wrappers, and JSON cut off before its closing brackets.