Introduction
The JSON Validator checks that text parses as JSON before you commit fixtures or send payloads. Syntax errors—trailing commas, single-quoted keys, unescaped quotes—break parsers everywhere. Fix the first reported error, validate again, and repeat until clean. When you need readability, use the JSON Formatter only after syntax passes so you do not prettify invalid text. JSON Schema validation is a separate concern; this tool focuses on raw parse correctness so your configs, APIs, and CI artifacts stay reliable.
Explore more in Tools, All Tools, or the JSON Tools category.
How to use
- Paste your JSON into the input area.
- Run validate to check syntax and parseability.
- Read the first error line carefully—fix it, then re-run.
- Repeat until validation passes.
- Optionally format with JSON Formatter for readability.
Use cases
- Validate fixtures before committing to repositories
- Check API responses before saving them as examples
- Verify config snippets copied from documentation
- Catch JSON errors before they reach production parsers
- Support debugging when JSON.parse fails in code
FAQ
- Does this validate JSON Schema?
- This tool focuses on JSON syntax. Schema validation is a separate step in your stack.
- What is the most common fix?
- Remove trailing commas and ensure keys use double quotes.
- Should I validate before formatting?
- Yes—fix syntax errors first, then format for readability.
- Is the validator free?
- Yes. DevToolDock provides this JSON Validator for free.
- Can I validate large JSON?
- Very large payloads may be slow in-browser—try a smaller excerpt if needed.