Best AI Code Reviewer in 2026? We Ran 4 in Parallel for 3 Weeks (146 PRs, 679 Findings) (opens in new tab)

Disclosure and context. A small team running a backend SaaS application (PHP/ReactJS, moderate-sized codebase, no connection to Sentry) was running its own evaluation of four AI code reviewers: CodeRabbit, Sentry Seer, Greptile, and Cursor BugBot. They asked for help on the data side. I built the ingester, captured the comments, and crunched the numbers. The conclusions below are the team's, drawn from the data. I work at Sentry, so one of the four reviewers is my employer's product. All four...