JSON Validator

Why validate JSON before you ship

Invalid JSON fails silently in the worst places: a production config reload, a mobile app crash on launch, or a data pipeline that skips malformed events. Syntax validation is the cheapest gate — it costs milliseconds and prevents hours of incident response.

Hand-edited files, exported spreadsheets converted to JSON, and LLM-generated payloads are the highest-risk sources. Run them through a validator before merge or deploy.

Common JSON syntax errors this tool catches

• Trailing commas after the last array element or object property
• Single quotes instead of required double quotes
• Unquoted object keys (JavaScript object shorthand, not valid JSON)
• Missing commas between properties or array items
• Unclosed brackets, braces, or strings
• Invalid Unicode escapes and control characters
• Numbers with leading zeros or malformed exponents

Line and column error reporting

JsonDrift points to the first parse error with line and column numbers so you can jump straight to the problem in your editor. Fix errors from the top of the file downward — resolving the first error often clears several downstream messages.

Syntax validation vs schema validation

This tool answers: 'Does this text parse as JSON?' Schema validation answers: 'Does this JSON match the shape and types we expect?' Use the JSON Validator for syntax; use the JSON Schema Validator when you need required fields, type checks, and enums.

Validate LLM and API JSON

Models and third-party APIs sometimes return almost-JSON: markdown fences, trailing commas, or truncated objects. Paste the payload here first. If it fails, read the error, fix locally, or consult our guide on fixing invalid JSON.