Skip to content

AI Code Reviewer

Server-powered

Get AI-powered code reviews with bug detection and security analysis online. Free code reviewer with improvement suggestions.

1 lines | 0 characters

What AI Code Review Checks

Security Vulnerabilities

Detects SQL injection, XSS, insecure deserialization, hardcoded secrets, and other OWASP Top 10 vulnerabilities in your code.

Bug Detection

Identifies potential null reference errors, off-by-one mistakes, race conditions, resource leaks, and logic errors.

Performance Issues

Spots inefficient algorithms, unnecessary re-renders, N+1 queries, memory leaks, and opportunities for optimization.

Best Practices

Checks adherence to language-specific conventions, design patterns, SOLID principles, and clean code standards.

Code Quality

Evaluates readability, maintainability, naming conventions, function complexity, and proper error handling.

Positive Feedback

Highlights what you are doing well so you know which patterns and practices to keep using in your codebase.

Supported Languages

Our AI code reviewer supports all major programming languages. Select a specific language for more precise analysis, or use Auto-detect to let the AI determine the language automatically.

JavaScriptTypeScriptPythonJavaC#GoRustPHPRubyC++SwiftKotlin+ many more

How It Works

1

Paste Your Code

Paste or type your code into the editor above. Select the programming language for best results.

2

AI Analysis

Our AI model analyzes your code for bugs, security issues, performance problems, and style violations.

3

Review Results

Get a detailed report with a quality score, issue list with fix suggestions, and positive highlights.

How to Use AI Code Reviewer

1

Paste code

Submit the code you want reviewed. Specify language for best results.

2

Choose review focus

Bugs, security, performance, style, or comprehensive. Focused reviews give specific feedback; comprehensive covers everything.

3

Review feedback

AI lists issues with explanations and suggested fixes. Each item includes severity (critical, warning, info).

4

Apply selectively

Verify each suggestion. AI sometimes proposes changes that break tests or don't apply. Treat as senior reviewer's first impressions.

When to Use AI Code Reviewer

Pre-PR self-review

Run a quick AI pass on your diff before opening the pull request. It catches the obvious stuff — style violations, simple bugs, basic security issues — so your reviewers can focus on architectural concerns instead of leaving comments about the same recurring footguns. Code review cycles get noticeably shorter.

Learning from code

Submit code you don't fully understand and ask for a senior-level review. You'll see what 'good code' looks like, learn why certain patterns are preferred, and pick up idioms specific to whatever language or framework you're using. It's a useful supplement for junior developers who don't have a senior engineer nearby.

Legacy code analysis

Old codebases tend to accumulate subtle issues that aren't worth a full refactor. An AI review identifies likely problems so you can prioritize what to address. It's helpful for technical debt assessments, modernization planning, and informal security audits where you need a starting list of concerns.

Solo developer safety net

Working alone with no team to review your code? An AI reviewer catches things you'd otherwise miss — security issues, common bugs, style inconsistencies — and while it's no substitute for an experienced colleague, it's substantially better than no review at all.

AI Code Reviewer Examples

Security issue found

Input
function login(user, pass) { return db.query('SELECT * FROM users WHERE name=' + user); }
Output
🚨 SQL injection vulnerability. User input concatenated directly into query. Use parameterized queries instead — db.query('SELECT * FROM users WHERE name=?', [user])

The model spots a classic SQL injection where user input is concatenated directly into a query, and suggests the parameterized fix. This is a textbook finding that any decent code review should catch.

Performance suggestion

Input
for (let user of users) { const score = users.filter(u => u.id === user.id).length; }
Output
⚠️ O(n²) complexity. Filtering inside the loop runs through the entire array on every iteration. Build a lookup map first — const map = new Map(users.map(u => [u.id, u])); — then look up by ID in constant time.

The model identifies the quadratic time complexity hidden in a nested filter and suggests the standard fix. Useful for catching scalability issues before they hit production with realistic data sizes.

Style suggestion

Input
function getUserName(u) { if (u && u.name) { return u.name; } else { return 'Unknown'; } }
Output
💡 Simplify with optional chaining and nullish coalescing — return u?.name ?? 'Unknown';

Same behavior, less code. The suggestion replaces a verbose null check with modern syntax that's idiomatic in current JavaScript. It's a style improvement rather than a bug fix.

Tips & Best Practices for AI Code Reviewer

  • 1.Treat AI review as a supplement to human review, not a replacement. The model misses architectural problems and anything that depends on business context, which is exactly what experienced reviewers catch.
  • 2.Read the suggestions critically. The model occasionally proposes changes that break tests or don't apply to your codebase — accept what's correct, ignore what isn't.
  • 3.For security-critical code, run dedicated scanners like Snyk or Semgrep alongside AI review. The model catches many issues but misses some that purpose-built tools handle reliably.
  • 4.Give the model context in your prompt. Style guides, framework conventions, and the target environment all change what 'good' looks like, and the more you describe, the more useful the review.
  • 5.Don't paste secrets. API keys, passwords, internal URLs in code being reviewed are a potential leak — sanitize before you submit.
  • 6.For a tighter feedback loop, use an IDE plugin like Cursor, GitHub Copilot, or Gemini Code Assist instead of copy-pasting into a web tool. Inline suggestions are dramatically faster to act on.

Frequently Asked Questions

It analyzes your code and provides feedback on bugs, security issues, performance problems, style, best practices, and readability. Think of it as a senior developer reviewing your PR — available any time and consistent in what it looks for, though missing the human judgment about architectural fit.