How to Validate JSON

The test

If JSON.parse(text) succeeds, the text is valid JSON. If it throws, it is not. A validator that only checks braces by eye will miss a trailing comma.

{
  "name": "Ada",
  "ok": true
}

parses. This does not:

{
  "name": "Ada",
}

Steps

1. Paste the document you intend to send or store — not a screenshot.
2. Run Validate. On the MultiConvers JSON formatter, that leaves your spacing alone and only reports parse success or failure.
3. If it fails, read the line and column, then look for a trailing comma, a missing quote, or a comment.

A worked failure

This document looks finished and is not:

{
  "name": "Ada",
}

The comma after "Ada" claims another property follows. Nothing does, so JSON.parse stops at that comma. Delete the comma and the same object parses. The line and column on the formatter are a starting point for that comma, not a schema review.

The limit

A document that parses can still be the wrong document. Missing "email" is valid JSON if your text never promised that field. This check is syntax only. It does not apply a JSON Schema, and it does not pretty-print.

Common failures

After it parses, format or pretty-print if you need to read it.