reviewable.io

Comments on GitHub commits about code quality, free for Open Source

Programming language aware diff for GitHub pull requests and commits, free for public repositories

Reports and thorough recommendations to optimize websites

Quality metadata badges for open source projects

Continuous inspection platform, free for Open Source

Static code analysis for Java, C/C++, C# and JavaScript, free for Open Source

AI-powered code review tool that integrates with GitHub/GitLab. Free tier includes 200 files/hour, 3 reviews per hour, and 50 conversations/hour. Free forever for open source projects.

Automated Code Review for Git. The free version includes unlimited users, public repositories, and one private repo.