ESLint in Browser

Lint JavaScript code locally using browser-based pattern matching.

Runs in your browserDeveloper

JavaScript Code

Issues

8
Line 1:1Disallow var declarations, use let/const insteadno-var

💡 Use let or const instead of var

Line 1:1Detect declared but potentially unused variablesno-unused-vars (basic)

💡 Remove or use the declared variable

Line 2:1Detect declared but potentially unused variablesno-unused-vars (basic)

💡 Remove or use the declared variable

Line 3:1Disallow console.log statementsno-console

💡 Remove or replace console statements

Line 4:6Require === and !== instead of == and !=eqeqeq

💡 Use === instead of == and !== instead of !=

Line 5:3Disallow alert(), confirm(), prompt()no-alert

💡 Use custom modal/dialog instead

Line 7:1Disallow eval() — security riskno-eval

💡 Avoid eval(), use safer alternatives

Line 8:1Disallow debugger statementsno-debugger

💡 Remove debugger statements before deployment

How It Works

1
Paste Code
Paste your JavaScript code into the editor.
2
Run Lint
The tool analyzes your code for common issues.
3
Review Issues
See warnings and errors with line numbers and descriptions.

Key Features

Pattern Matching
Detects common JavaScript code issues.
📊
Issue Report
Clear list of warnings and errors with locations.
💡
Fix Suggestions
Guidance on how to resolve each issue.
🔒
Local Processing
Code is analyzed entirely in your browser.

Use Cases

Quick code review before committing
Find common JavaScript mistakes
Check code quality without IDE setup
Learn best practices from lint suggestions

Frequently Asked Questions

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