About JSON Formatter
JSON looks simple until a single missing comma silently breaks your build. The JSON Formatter on FIFITOOLS lints, prettifies and minifies JSON entirely in your browser so you can spot mistakes instantly without uploading anything to a server.
Paste in a payload from an API response, a webhook log or a config file and the tool will indent it cleanly, flag the exact line where parsing fails, and let you collapse deeply nested objects so you can focus on the part you care about.
How to use it
- 1Paste your JSON into the input box on the left.
- 2Tap Format to beautify it with proper indentation, or Minify to strip whitespace.
- 3If the JSON is invalid, the error message will tell you the line and column of the problem.
- 4Copy the cleaned output with the Copy button when you're done.
When it comes in handy
- Reading minified API responses from REST or GraphQL endpoints.
- Debugging malformed webhook payloads from Stripe, GitHub or Slack.
- Cleaning up package.json, tsconfig.json or other dev config files.
- Producing compact JSON to embed inline in HTML or environment variables.
Frequently asked questions
Does the JSON get uploaded anywhere?
No. The entire parser runs in your browser using JavaScript's native JSON object. Nothing is sent to a server.
What's the maximum file size?
There is no hard limit, but very large files (tens of MB) may slow down the browser. For huge files, a desktop editor like VS Code is better.
Can it format JSON5 or comments?
Not currently — the formatter targets strict JSON. Comments and trailing commas will trigger a parse error.