How to check whether a string parses as valid JSON

1. Paste the JSON

   Drop the candidate text into the "JSON" field. Both objects (`{ … }`) and arrays (`[ … ]`) parse. Trailing commas, single quotes, and comments are NOT valid JSON and will be flagged.

2. Press Run

   Result returns `valid` (boolean), and on failure an `error` string describing roughly where parsing broke (line/column if the parser provides it). Success doesn't reformat — the input is unchanged.

3. Common error shapes

   `Unexpected token } in JSON` usually means a trailing comma; `Unexpected end of JSON input` means an unclosed `{`, `[`, or `"`; `Unexpected non-whitespace character` after a complete value means extra text after the document.

4. Not a schema check

   This validates SYNTAX only — that the text is parseable JSON. It does NOT verify the data matches an expected shape; for that pair with `json-schema-validator-online` or a real validator library in your build.