Code Bug Detector

Paste code to detect common bugs, potential errors, and code quality issues. Supports all major languages.

How It Works

This tool performs heuristic-based static analysis entirely in your browser. It scans your code line by line and applies pattern-matching rules to detect common bugs and code quality issues. No data is sent to any server.

• Error-level checks — detects likely bugs such as assignment in conditionals, unclosed brackets, use of undefined variables patterns, comparison type mismatches, and missing break statements in switch cases
• Warning-level checks — flags suspicious patterns like unused variables, console.log in production code, empty catch blocks, magic numbers, deeply nested code, and deprecated function usage
• Info-level checks — suggests improvements such as using strict equality, preferring const over let, and adding error handling to async code

This is a pattern-based analyzer, not a compiler — it catches many common mistakes but cannot replace a full linter or type checker. It works best as a quick first-pass review.