JSON Formatter
Paste messy JSON and format it with proper indentation, or minify it to strip whitespace. Also validates your JSON and tells you exactly where the error is if something's broken. Everything runs in the browser.
How to use
- Paste your JSON into the input box - raw, minified, or broken.
- Click Format to beautify it, or Minify to compact it.
- If there's a syntax error, it'll tell you where. Copy the output when you're done.
Related tools:
Minified JSON and API responses are often one long line of text - technically valid but completely unreadable when you are trying to debug or understand the structure. Prettifying adds indentation and line breaks so the hierarchy is immediately visible. This tool handles the formatting both ways.
Validation catches syntax errors before you send invalid JSON to an API or store it in a database - missing commas, trailing commas (not valid in standard JSON), unquoted keys, single quotes instead of double quotes. These are the errors that cause silent failures or confusing error messages from downstream systems.
Frequently Asked Questions
What is the difference between JSON and JavaScript objects?
JSON is a strict data format: keys must be double-quoted strings, no trailing commas, no comments, no undefined values, no functions. JavaScript objects are more flexible. Valid JavaScript objects are often not valid JSON, and vice versa: JSON strings parsed in JavaScript become objects, but they are not identical syntaxes.
What is minified JSON and why is it used?
Minified JSON removes all whitespace (spaces, tabs, line breaks) that is not inside a string value. It reduces file size, which matters for API responses and stored config files where bandwidth or storage is a consideration. Human readability is sacrificed for compactness.
Does JSON support comments?
No. Standard JSON has no comment syntax. This is a deliberate design choice by the JSON spec author Douglas Crockford. If you need comments in config files, consider JSON5, JSONC, or YAML instead.