Last updated: March 2026
What Is the Code Review Tool?
The Code Review Tool is a free online code analysis tool that uses AI to find bugs, security vulnerabilities, performance bottlenecks, and code quality issues in your code. It supports 20+ programming languages and provides a scored report with line-by-line feedback, making it the fastest way to get a professional-quality code review without waiting for a teammate.
Unlike basic linters that only check syntax and formatting, this tool understands your code's logic. It can detect null pointer risks, SQL injection vulnerabilities, missing error handling, race conditions, and dozens of other issues that require understanding what the code actually does — not just how it's formatted.
How to Review Your Code
1. Paste code into the editor (up to 500 lines or 15,000 characters).
2. Choose review categories — toggle bugs, security, performance, smells, style, or accessibility.
3. Click Review Code for an AI-powered analysis with scores, issues, and fix suggestions.
4. Filter and fix — filter issues by severity, expand cards for details, copy fix code snippets.
Key Features
The code review tool scans six categories of issues: bugs and logic errors, security vulnerabilities, performance problems, code smells, style violations, and accessibility issues. Every finding includes a severity level, line reference, description, and a concrete code fix you can copy and paste. A 0-100 score gauge gives you an instant quality snapshot.
The editor shows colored line markers — red for critical bugs, yellow for warnings, blue for info — so you can see problem areas at a glance. Filter buttons let you focus on what matters most, and the full review exports as Markdown for pull request comments or documentation.
Frequently Asked Questions
How does the code review tool work?
Paste your code, select which types of issues to scan for, and click Review Code. The AI analyzes your code for bugs, security vulnerabilities, performance problems, code smells, and style issues, then returns a scored review with line-by-line feedback and fix suggestions.
What languages does the code review tool support?
The tool supports 20+ languages including JavaScript, TypeScript, Python, Java, C, C++, Go, Rust, Ruby, PHP, Swift, Kotlin, SQL, HTML/CSS, React/JSX, Vue, Shell/Bash, C#, Dart, Scala, and R. Auto-detection identifies your language automatically.
Is my code kept private?
Yes. Your code is sent to the Anthropic API using your personal API key for real-time analysis. Nothing is stored or logged by this tool. All data disappears when you leave the page.
Can this replace manual code reviews?
The AI code review tool is a powerful complement to human review, not a replacement. It catches many common issues instantly, but complex architectural decisions and business logic still benefit from human judgment. Use it as a first pass before or alongside peer review.
What do the severity levels mean?
Critical issues are bugs or security vulnerabilities that could cause crashes, data loss, or security breaches. Warnings are significant problems like performance issues or code smells. Info items are style suggestions and best practice recommendations.