No comments β `//` or `/* */` makes it invalid JSON
No `undefined`, `NaN`, or `Infinity` β only `null`
Newlines inside strings must be escaped as `\n`
Debugging tip
The reported error position often points *after* the real problem β check the comma or quote on the preceding element first. Formatting also doubles as validation: if it formats and folds, it parses.
Frequently Asked Questions
A JSON formatter is an online tool that takes raw or minified JSON data and reformats it with proper indentation and line breaks, making it easy to read and debug. This is also known as 'pretty printing' JSON.
Paste your JSON into the input area above and click 'Format / Beautify'. You can choose between 2 spaces, 4 spaces, or tab indentation. The formatted output appears instantly and can be copied with one click.
Click 'Validate' to check your JSON for syntax errors. If the JSON is invalid, the tool reports the exact error message along with the line number and column where the problem was found, making it easy to fix.
JSON minification (or compression) removes all unnecessary whitespace, line breaks, and indentation from JSON data. This reduces file size for faster network transmission and storage. Click 'Minify' to compress your JSON.
After formatting or validating your JSON, switch to 'Tree View' to see a collapsible, hierarchical representation of your data. Click the arrows to expand or collapse objects and arrays, making it easy to navigate complex nested structures.
Yes! You can either click 'Upload File' to select a .json or .txt file from your computer, or simply drag and drop a file directly onto the input area.
They are the same thing. 'Format', 'beautify', and 'pretty print' all refer to adding proper indentation and line breaks to make JSON human-readable. Our tool supports 2-space, 4-space, and tab indentation styles.
Use the 'Validate' button to check your JSON. The JSON syntax checker will identify errors and report them with line numbers so you can quickly locate and fix issues like missing commas, unmatched brackets, or invalid values.
Absolutely. All processing happens entirely in your browser β your JSON data is never sent to any server. This tool works offline once loaded, ensuring complete privacy for sensitive data.
This tool supports standard JSON as defined in RFC 8259. It handles objects, arrays, strings, numbers, booleans, and null values. Nested structures of any depth are fully supported in both the formatter and tree viewer.