What JSON Formatter does
Format JSON locally with lossless large integers, configurable indentation, and deterministic key ordering.
Also searched as format, beautify, pretty print, prettify, indent, reformat, unminify, expand.
Parse once in Rust/WASM
Preserve numeric spelling
Serialize with your indentation and ordering rules
Formatting is structural
Whitespace changes, but values and array order do not. Optional key sorting is explicit because object-key order can still matter to humans and downstream text comparisons.
Large integers stay intact
The engine does not route input through JavaScript's floating-point JSON parser, avoiding silent precision loss above 2^53−1.
JSON Formatter FAQ
What indentation can I use?
Choose two spaces, four spaces, tabs, or a custom width from one to eight spaces in the workbench.
Does jsontools.me upload my JSON?
No. The document is parsed and processed by json-buf inside a dedicated WebAssembly worker on your device.
Does it work offline?
Yes. After the application shell and engine have loaded once, the installable PWA keeps the tools available without a network connection.