Paste JSON
Result
How to use
1. Paste JSON on the left (or drop a .json file above). 2. Click Format to pretty-print it, Minify to squeeze it to one line, or Validate to check it without changing anything. 3. If it is invalid, the notice shows the line and column of the first error and jumps the cursor to it. 4. Copy the result or download it as .json.
FAQ
Is my JSON uploaded? No. Parsing, formatting and validation all run in your browser with the built-in JSON parser; nothing passes through our server.
How are errors located? The parser reports the character position of the first error; the tool converts it to a line and column and shows the offending line, so a missing comma or quote is easy to find. The most common cause is a trailing comma — strict JSON does not allow one.
What about duplicate keys? Standard JSON keeps the last value when a key repeats in the same object. The validator warns you about repeats (with their line numbers) instead of silently dropping them.
How large a file can I paste? Anything a browser tab can hold, but very large files (tens of MB) get slow. For everyday config and API responses — up to a few MB — it is instant.