How it works
The formatter parses your input with the browser’s native JSON.parse, then
re-serialises it with JSON.stringify at your chosen indentation. Because both
steps run on your device, the tool works offline and your data is never
transmitted.
When to use it
Reading an API response pulled from network inspector output, diffing two config files that differ only in whitespace, or checking whether a payload is valid JSON before pasting it into something less forgiving.
A worked example
Trailing commas are the most common reason valid-looking JSON is rejected. This is invalid, and the error will point at line 3:
{
"name": "example",
"tags": ["a", "b",],
}Limitations
Very large documents are parsed on the main thread and may briefly block the page. JSON with comments (JSONC) and trailing commas is not valid JSON and will be reported as an error.