Format and validate
Pretty-print compact API responses and identify invalid JSON syntax before using the data.
Free, private developer tool
JSON Formatter Online
Format, beautify, validate and minify JSON instantly. Paste text or upload a JSON file, inspect clear syntax errors, then copy or download the result—without sending your data to a server.
Input JSON0 characters
Formatted output
Minify JSON
Remove indentation and line breaks to produce a compact JSON string for transport or storage.
Private by design
Processing stays inside your browser. No account, paste history or server upload is required.
Free online JSON formatter and beautifier
A JSON formatter turns compact or inconsistently indented JSON into a readable structure. This online JSON beautifier uses standard parsing and stringification, so objects, arrays, strings, numbers, booleans and null values retain their data types. Choose two spaces, four spaces or tabs, and optionally sort object keys for easier comparison.
How to format JSON online
- Paste JSON into the input editor or upload a
.jsonfile up to 5 MB. - Select your indentation and decide whether object keys should be sorted.
- Choose Format JSON for a pretty print, Validate for a syntax check or Minify for compact output.
- Copy the result or download it as a new JSON file.
JSON validator for common syntax problems
Valid JSON requires double-quoted property names and strings, balanced braces and brackets, and commas between neighbouring values. Trailing commas, comments, single-quoted strings, undefined and unquoted keys are valid in some JavaScript contexts but are not valid JSON. This checker reports parsing errors rather than silently changing your data.
JSON formatter questions
How do I format JSON online?
Paste or upload your JSON, choose an indentation style and select Format JSON. The tool validates the syntax and produces a readable, pretty-printed result that you can copy or download.
Is this JSON formatter private?
Yes. Formatting, validation and minification happen locally with your browser's JSON parser. Your JSON is not sent to Esperto's server.
What is the difference between formatting and minifying JSON?
Formatting adds indentation and line breaks to make JSON easier to read. Minifying removes unnecessary whitespace to create a smaller single-line representation without changing the data.
Can the tool validate invalid JSON?
Yes. Select Validate to check the syntax. If parsing fails, the tool displays the browser's error message and, where available, the line and column of the problem.