About the JSON Formatter / Validator
JSON (JavaScript Object Notation) is the format APIs, config files and databases use to exchange data. But raw JSON is often delivered as one long, unreadable line. A formatter re-indents it into a clean, nested structure so you can actually read it, and a validator catches the missing comma or bracket that's breaking your code.
This tool formats, beautifies and validates JSON entirely in your browser. Paste in a messy blob and get back neatly indented output, or minify it back down to a single line. Nothing is uploaded, so it's safe to paste API responses containing private data.
How to use it
- 1Paste your JSON into the input box.
- 2Click Format to indent and beautify it, or Minify to strip whitespace.
- 3If the JSON is invalid, the tool points out where the error is so you can fix it.
- 4Adjust the indentation to 2 or 4 spaces to match your project's style.
- 5Copy the cleaned-up result to your clipboard.
Common uses
- →Reading an API response that arrived as one unreadable line.
- →Finding the syntax error in a config file that won't parse.
- →Minifying JSON to reduce payload size before shipping.
- →Tidying up data before pasting it into documentation or a ticket.
- →Learning JSON structure while studying web development.
Tips & good to know
- Valid JSON uses double quotes around keys and strings — single quotes will fail.
- Trailing commas after the last item are not allowed in strict JSON.
- Minify for production payloads, but keep a formatted copy for humans to read.
Frequently asked questions
- Is my JSON sent to a server?
- No. Formatting and validation run entirely in your browser, so even sensitive API data stays on your device.
- Why does it say my JSON is invalid?
- Common causes are single quotes, trailing commas, or a missing bracket. The tool highlights where parsing failed so you can fix it.
- Can it minify as well as beautify?
- Yes. Format expands JSON for readability; Minify collapses it to the smallest valid single-line form.