AI Code Review Tools

AI Code Review: How It Works and 5 Tools You Should Know

Swimm: Offers a "Free" plan for up to 5 users and 1 private repository, with unlimited documents. It focuses on in-code documentation and keeping it in sync with the codebase.

Codacy: Has a "Free Developer Plan" that includes Codacy Guardrails for real-time analysis of AI-generated code within your IDE (VSCode, Cursor, Windsurf). It also offers free code scanning for open-source projects with unlimited public projects and unlimited lines of code, covering code quality and security scanning across many languages.

DeepCode (now integrated with Snyk): The "Free Tier" is designed for individual developers, open-source projects, and small teams. It provides basic AI code analysis for public repositories, a limited number of code reviews per month, and standard machine learning insights. It supports multiple programming languages and integrates with GitHub, GitLab, and Bitbucket.

Code Climate: Offers an "Open Source" plan that is free for unlimited public repositories and unlimited users, with GitHub pull request integration. This is specifically for open-source projects. For private repositories, they offer a 14-day free trial.

Bito AI: Provides a "Free" plan with unlimited AI pull request summaries, 75 AI chat requests per day, and 300 AI code completions per month. It supports many programming languages and integrates with various IDEs.

CodeRabbit: Has a "Free Plan" that offers PR summarization for each pull request, with unlimited public and private repositories. They also have a free "OSS Plan" for open-source projects, which includes unlimited public repositories and reviews. There are usage limits on files per hour, files per PR, and reviews per hour in the free tiers.

Which is the "best" free option depends on your specific needs:

For AI-powered code suggestions and chat in your IDE (like a Copilot alternative): Bito AI offers a generous free tier with daily AI chat requests and monthly code completions. Codacy's Guardrails also provide real-time AI analysis within the IDE.

For comprehensive static analysis and security for open-source projects: Codacy and Code Climate are excellent choices, offering unlimited public repositories. DeepCode also offers analysis for public repositories.

For in-code documentation that stays updated: Swimm offers a useful free tier for individual projects or very small teams.

For AI-driven code reviews and PR summarization: CodeRabbit offers free PR summarization for both public and private repositories, and is free for open-source projects.
Overall Considerations:

"Free" often means limited: Be aware of daily/monthly usage limits, team size restrictions, and limitations on private repositories.

Focus: Some tools are more geared towards security (Codacy, DeepCode), others towards general code quality (Code Climate), AI assistance (Bito AI, CodeRabbit), or documentation (Swimm).

Integration: Most integrate with popular Git platforms (GitHub, GitLab, Bitbucket) and IDEs.
Given the variety, there isn't a single "best" free option without knowing your exact use case.

If you're an individual developer working on personal or open-source projects and want AI assistance, Bito AI or CodeRabbit's free plans are very strong.

If you need robust static analysis for an open-source project, Codacy or Code Climate would be highly beneficial.