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JSON Lint

The classic JSON Linter. Instantly check your syntax, uncover hidden errors, and format invalid JSON to valid structures.

Input JSON
Characters0
Lines0
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Waiting for input…
Paste JSON on the left to begin linting
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Real-time Linting
Instantly evaluate JSON code using the world's most popular JSON processing rules.
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Detailed Output
ASCII error pointers reveal exactly what went wrong and where.
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Fix Missing Quotes
Sometimes your JSON isn't quite valid. Auto-fix makes it perfect.

What Is JSONLint?

JSONLint is the original, open-source linter for JavaScript Object Notation format. Developed years ago, it remains one of the most reliable and thorough syntax checkers for JSON payloads available on the web.

  • Detects missing commas, trailing commas, and unquoted strings.
  • Draws a trace map pointing directly to the exact character error.
  • Supports formatting to make minified server responses readable.

Why Use JSONLint Online?

  1. Copy output from an API response and drop it in the validator.
  2. If there's an issue, JSONLint will highlight it immediately.
  3. Save debugging time and avoid tracking down backend 500 errors.