JSON Validator

JSON Validator parses your text against the JSON specification and reports exactly where commas, quotes, or brackets break syntax.

It is the fast gate before you paste webhook configs, environment secrets, or CMS import files into production systems.

A single trailing comma in a Firebase or Vercel config JSON fails deployment at 2 AM—validate before push.

Low-code exports claim “JSON ready” but often include BOM characters or smart quotes from Word.

• Pre-flight check on package.json edits before npm publish
• Validate webhook test payloads from customer support tickets
• Confirm exported Notion or Airtable JSON imports
• CI manual gate when IDE plugins are unavailable on a server
• Teaching JSON syntax with immediate error feedback

1. 1Paste JSON into the validator input.
2. 2Run validate—or watch live validation if the workspace updates as you type.
3. 3Read the error message and line or position hint.
4. 4Fix the syntax issue in your editor.
5. 5Re-validate until the pass indicator shows clean parse.

• Use JSON Formatter after validation passes to pretty-print for review.
• Watch for smart quotes “ ” from copied documentation—they are invalid JSON delimiters.
• UTF-8 BOM at file start causes cryptic errors—re-save without BOM in your editor.
• Validate minified and formatted versions separately when debugging CI diffs.

• Syntax pass does not mean schema correctness—business rules need JSON Schema or app-level checks.
• Multi-megabyte files may freeze the tab briefly.
• Common mistake — validating JavaScript object literal syntax: JSON requires double-quoted keys.