AI Bug Detector Free Online
Paste your code and let AI find syntax errors, security vulnerabilities, performance bottlenecks, and logic bugs — across 14 languages, instantly, no signup required.
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Analysis Report
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Paste code and click "Detect Bugs" to start
AI Bug Detector — Find Code Errors Instantly
The AI Bug Detector is a free online tool that uses large language models to scan your code for bugs, security vulnerabilities, performance issues, and style problems. Whether you are debugging a JavaScript async function, auditing a Python script for injection risks, or reviewing Java for memory leaks, the AI surfaces issues that traditional linters miss — and explains exactly how to fix them. It supports 14 languages including JavaScript, TypeScript, Python, Java, Go, Rust, Kotlin, and SQL, and requires no account or installation.
How to Use the AI Bug Detector
- Select your language — choose from 14 options in the language dropdown.
- Pick an analysis mode — Full Analysis, Security Audit, Performance Review, or Quick Check.
- Paste your code — or click "Load Sample" to try a snippet with intentional bugs already embedded.
- Click "Detect Bugs" — the AI analyzes your code and returns a detailed markdown report in seconds.
- Review and copy — read the findings, copy the corrected code, or download the full report as a text file.
What the AI Bug Detector Finds
Syntax & Logic Errors
Missing brackets, wrong operators, off-by-one errors, broken conditionals, and mismatched types.
Security Vulnerabilities
SQL injection, XSS, command injection, unsafe deserialization, hardcoded credentials, and CSRF risks.
Performance Bottlenecks
O(n²) loops, blocking I/O, redundant computations, memory leaks, and inefficient data structures.
Best Practice Violations
Mutable default arguments, unused variables, missing error handling, poor naming, and anti-patterns.
Async/Concurrency Bugs
Missing await, race conditions, unhandled promise rejections, and blocking event loops.
Fixed Code
Full or targeted corrected versions of your code so you can apply the fix immediately.
AI Bug Detector vs Traditional Linters
| Capability | ESLint / Pylint | AI Bug Detector |
|---|---|---|
| Syntax errors | Yes | Yes |
| Style / formatting | Yes | Yes |
| Logic errors | Limited | Yes |
| Security vulnerabilities | With plugins | Yes (built-in) |
| Natural language explanation | No | Yes |
| Auto-corrected code output | Partial (--fix) | Yes |
| Supports 14 languages | Separate tools | Yes (one tool) |
| No config / install needed | No | Yes |
Real-World Use Cases
- ✓Debug a failing API handler before deploying to production
- ✓Audit a login form for XSS and SQL injection vulnerabilities
- ✓Review a data-processing script for memory leaks before running on large datasets
- ✓Learn best practices from AI explanations while studying a new language
- ✓Quickly verify legacy code you inherited before refactoring
- ✓Find the bug in a sorting algorithm that passes unit tests but fails edge cases
Frequently Asked Questions
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