GitHub Copilot is the strongest fit here because it integrates directly into pull request workflows, can summarize diffs, flag suspicious changes, and suggest test coverage gaps without leaving your editor or code review interface. It understands code context well enough to spot logic shifts that look syntactically fine but may introduce regressions. Cursor is worth considering if you want a full AI-native editor that can run the changed code and reason about side effects interactively. Claude Sonnet is a solid alternative when you want to paste a large diff and get a thorough plain-language analysis of what changed and what could break. Deepseek Coder is a free option that handles code-focused review tasks competently at no cost.