JSON Linter – Detect JSON Errors Online
Lint your JSON to catch syntax errors, duplicate keys, trailing commas, and structural issues. Our free JSON Linter helps you write clean and standards-compliant JSON.
Why Lint Your JSON?
Your JSON looks right but something's off. Maybe a missing comma, a trailing comma that shouldn't be there, or inconsistent formatting. A linter catches these issues before they cause runtime errors. This tool checks your JSON syntax and highlights problems with clear error messages.
What This Linter Checks
SSyntax
- • Bracket matching
- • Quote validation
- • Comma placement
- • Colon syntax
QQuality
- • Duplicate keys
- • Trailing commas
- • Comment detection
- • Style consistency
FFixes
- • Error positioning
- • Line numbers
- • Code snippets
- • Fix suggestions
About JSON Linter
A JSON linter checks your JSON for syntax errors and common issues beyond basic validation. It points out problems line by line with specific messages about what's wrong. This helps you fix JSON before it causes runtime errors in your application.
How the linter works
Paste your JSON in the input box and click Lint JSON. The tool parses your input and checks for syntax errors, comments, trailing commas, and other issues. Each problem is listed with its line number, column, and a description.
Errors show in red with severity indicators. Click on an issue to see the problematic code snippet. Fix the issues and run the linter again until your JSON is clean.
When you'd use this
Your JSON config file isn't loading and you need to find the syntax error. Or you're writing JSON by hand and want to catch mistakes early. This tool also helps when reviewing JSON from external sources before using it.
The linter checks syntax only, not semantics. It won't tell you if required fields are missing or values are wrong. For schema validation, use our JSON Schema Validator tool instead.
Questions
What issues does the linter find?
Syntax errors, invalid characters, comments (not allowed in JSON), trailing commas, and malformed strings or numbers.
Does it support JSON5?
No, this linter checks strict JSON. JSON5 features like comments and trailing commas will be flagged as errors.
How accurate are line numbers?
Line numbers are calculated from your input. They should match your editor if you haven't modified the text since pasting.
Can it fix errors automatically?
No, this tool only reports issues. Use the error messages to manually fix your JSON, then run the linter again.
What's the difference between linting and validating?
Linting finds syntax issues and reports details. Validation just says valid or invalid. Linting gives you more information to fix problems.