Format and validate JSON without sending it to a server

JSON is a text format used by APIs, configuration files, and data exports. When a response spans one long line, it is difficult to inspect. Formatting adds indentation so nested objects and arrays become easier to see; minifying removes insignificant whitespace so the file is shorter. Neither operation changes the data values when parsing succeeds.

Validate before changing anything

Paste a sample into the JSON formatter and validator and choose “Format and validate.” The tool parses the input in your browser. If it is valid JSON, it produces a readable representation with indentation. If parsing fails, the tool reports an error instead of silently guessing what you meant.

A common mistake is a comma after the final property of an object. Another is using single quotes: JSON requires double quotes for property names and string values. Comments are not part of standard JSON either. For example, {"enabled": true} is valid, whereas {enabled: true,} is not.

Formatting versus minifying

Choose formatting while debugging, reviewing a change, or reading a response. Choose minifying when a receiver expects compact JSON. Keep in mind that minifying reduces whitespace, not the size of images or files represented within strings. It also does not fix an invalid input.

After parsing, our browser implementation serializes the result with JavaScript’s JSON handling. If your workflow depends on preserving the original spacing, numeric formatting, or duplicate object keys exactly as written, keep the source alongside the reformatted copy. A JSON object with duplicate keys can lose information when parsed and serialized.

Handle secrets carefully

Data in this formatter stays in the current browser tool rather than being sent to the OneFreePlace server. Still, avoid pasting live API keys or customer records into an unfamiliar shared computer, browser extension environment, or public screenshot. Redact values when posting a sample in a forum or issue tracker. When done, clear the input and your clipboard if necessary.