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Free Online Tool
JSON Repair
Free online JSON repair tool for malformed API payloads, LLM outputs, and log snippets. Fix syntax and validate quickly.
Repair Malformed JSON
Auto-repair features
- Fixes trailing commas
- Converts single quotes to double quotes
- Quotes unquoted object keys
- Strips Markdown code blocks
What problem does this tool solve?
Invalid JSON blocks integrations, breaks automation scripts, and causes avoidable parser failures in production workflows.
How to use JSON Repair
- Paste broken JSON from logs, API responses, or model output.
- Run repair and validation to fix structural syntax issues.
- Copy valid JSON for tests, schema validation, and downstream services.
FAQ: JSON Repair
Can this fix single quotes and trailing commas in JSON?
Yes. It normalizes common syntax issues to strict JSON format for parser compatibility.
Will JSON Repair guess missing fields automatically?
No. It fixes structure, but unknown values should come from the original source system.
Is JSON repair useful for AI output cleanup?
Yes. It is especially helpful when enforcing schema-ready responses from LLM pipelines.