We wanted to add an AI Code Review to our existing code review process, not to replace human reviewers.
It is primarily used as a first-pass code review for the developer that submitted the PR, but the comments made by tool can also start conversations between humans.
Our small engineering team of five did trials of four different AI-powered code review tools:
- CodeRabbit
- Cubic.dev
- Cursor’s BugBot
- Claude Code Review
We opted to do minimal customization of each.
TDLR - we’re going with Cubic.
Evaluations
Claude Code Review
The format of this was all wrong - one big comment on the PR, rather than in-line comments. The reviews were so “fluffy” with overly positive language and checklists, it was actually hard to get any signal from the noise. I did update the prompt to be more succinct in its responses but that didn’t move the bar much.
Each PR update triggered a new big comment, and it was in the way so we shut it off after a few days.
This was the cheapest solution, costing a few cents per review for us.
Cursor’s BugBot
Seemed tilted towards bugs and security. Overall the comments weren’t super helpful. It did have a nicer integration than Claude Code in that it did per-line comments, and even had a way to have a background agent fix the issue.
This was the most expensive solution at $40/user/month, twice the cost we pay for Cursor itself (we’re also moving away from Cursor but that had nothing to do with this review)
CodeRabbit
Line-by-line comments, caught real practical bugs and issues. You have to turn off a lot of the features immediately, like the poems and ASCII art - way too much cutesy stuff out of the box.
CodeRabbit also includes diagrams and visualizations for the changes, which were often just in the way, since our team is already familiar with the architecture of the codebase.
It generated a wall of text with each review, but it at least used Github’s collapsable markdown sections so that it wasn’t overly intrusive.
While it caught real issues, it also has a lot of “Nitpicks” and “Refactor Suggestions”, so we’d ignore 75% or more of the comments it made.
CodeRabbit has a lot of potential, and oddly enough I had only found out about it because of their billboard on I-35 in Austin.
Pricing-wise, $24/month/user if paid annually, $30 if paid monthly.
Cubic
A YC company, the newest one on the block. Less nit-picky than the rest, it caught some real issues. Cubic has line-by-line comments like CodeRabbit and Bugbot.
It was the least noisy of the bunch and most useful. The comments were succinct and to the point, and the PR summary that it writes was useful to. On some small PRs, the only comment was that it had no comments, which was nice in a UNIXy-philosophy-kind-of-way.
They do have their own review app, rather than using Github’s Pull Request review page, which had similar diagrams to CodeRabbit, but my team just didn’t find them useful.
We didn’t test the “Fix with Cubic” feature, but it looks like they have a way for a background agent to update the code.
Pricing-wise, $24/month/user if paid annually, $30 if paid monthly, same as CodeRabbit.
Conclusion
We’re going with Cubic at the end. After all of the trials ended last week, my team felt the void of not having any of these tools active and asked if we could get Cubic turned back on, so we upgraded to paid last month and we’ve been pretty happy since.