Missing double quotes
Object keys must be wrapped in double quotes, such as "name": "Toolbye".
How to Fix JSON Validation Errors
Understand the most common JSON syntax issues quickly, then jump back to the JSON tool to validate and repair your payload.
Common JSON Validation Errors
Single quotes used in strings
Strict JSON does not allow single quotes for keys or string values.
Missing or extra commas
Each property and array item must be separated by exactly one comma.
Trailing comma at the end
JSON rejects a comma after the last property or array item.
Bracket mismatch
Ensure object and array brackets are paired correctly from start to end.
Comments in JSON
Comments are valid in JS, but not in strict JSON documents.
How to locate JSON errors fast
- Paste your payload into the JSON Formatter input panel.
- Check the validation status and line/column location returned by the parser.
- Fix one issue at a time, then validate again until the payload becomes valid.
FAQ: Fixing invalid JSON
Why does valid JavaScript become invalid JSON?
JSON is stricter than JavaScript. Comments, single quotes, and trailing commas are common reasons.
What should I fix first when multiple errors exist?
Fix the earliest reported line first. Later errors are often side effects of the first syntax break.
Can this page repair JSON automatically?
This page explains the fix process. Use the JSON tool page to validate and format after each correction.
How do I avoid JSON errors in API payloads?
Validate payloads before sending requests, and keep your API examples in strict JSON format.
Go to tools
JSON Formatter & Validator
Open the main JSON tool to validate and fix your input immediately.
JSON Format Error Online Checker
Need a quick online check flow? Start from this scenario page and jump into the tool.
Timestamp Converter
Convert Unix timestamps while debugging API response fields.
Base64 Encode / Decode
Decode and encode payload fragments while troubleshooting API data.