JSON Formatter

How to format JSON online?

Paste any JSON into the input box and Lime Kit's JSON Formatter pretty-prints it instantly using your choice of 2-space, 4-space, or tab indentation. If the JSON is invalid, the error message points to the exact line and column so you can fix it fast. Everything runs locally in your browser — your data is never uploaded to a server.

Validate many JSON documents at once

Paste several JSON documents — one per line (JSON Lines / NDJSON), separated by blank lines, or simply one after another — and every one is checked. Each invalid document is listed with its error and its line and column in your input, and Go to jumps straight to it. To check files, drop any number of .json or .jsonl files on the tool: each gets a valid/invalid verdict and the exact problem, and Open loads it into the editor to fix.

Need the opposite? Hit Minify to collapse formatted JSON down to a single compact line, ideal for pasting into config files or API requests. With several documents, Minify puts each on its own line, producing JSON Lines.