Best Free AI Code Review Tools in 2026
Every tool here will leave comments on your pull requests. What separates them is who is allowed to use the free tier, and that turns out to be the only question that matters.
Three arrangements hide behind the same word. Free for open source means public repositories only, and the moment you make a repo private you are on a paid plan. Free for one developer means the tool works on your private code, and the second person to join needs a seat. Free with a review cap means everyone can use it until you run out of reviews for the month.
A comparison table that just says "Free" for all three is worse than no table.
How these rate, aggregated across platforms
Scores from Toolradar, aggregated across G2, Capterra and SourceForge.
| Tool | Aggregated rating | Reviews |
|---|---|---|
| Sourcery | 4.8 | 17 |
| CodeRabbit | 4.4 | 119 |
| Codacy | 4.4 | 31 |
| Graphite | 3.8 | 3 |
GitHub Copilot and Greptile carry no aggregated rating in the directory.
CodeRabbit's 119 reviews is the only sample here with any weight, and even that is small by software-directory standards. AI code review is roughly two years old as a product category, so the review corpora have not had time to build. Sourcery's category-leading 4.8 rests on 17 reviews and Graphite's 3.8 on 3, which means neither number should move your decision an inch.
Treat this table as evidence that nobody has been badly burned yet, not as a ranking.
What each free tier actually covers
Prices verified against Toolradar's pricing records, all checked between 15 and 25 August 2026.
| Tool | Free tier | First paid tier | Price checked |
|---|---|---|---|
| CodeRabbit | Yes | Pro, $24/dev/month | 23 Aug 2026 |
| Sourcery | Yes | Pro, $12/month | 23 Aug 2026 |
| Codacy | Yes | Pro, $18/month | 18 Aug 2026 |
| GitHub Copilot | Yes | Pro, $10/month | 16 Aug 2026 |
| Graphite | Hobby | Starter, $20/user/month annual | 25 Aug 2026 |
| Greptile | No | Cloud, $30/active dev/month | 15 Aug 2026 |
Two things fall straight out of that table.
Greptile has no free tier at all and belongs in this article only because it is the tool people keep expecting to find here. And $30 per active developer is the highest per-seat price in the category, roughly triple GitHub Copilot's.
The second is that the cheapest paid escape hatch is Copilot at $10, and it is the one tool here that is not primarily a code reviewer. That tension runs through everything below.
CodeRabbit
CodeRabbit is the one most teams land on, and the free tier is genuinely usable: it reviews public repositories without limit, and it reviews them properly rather than posting a summary and calling it a day.
It reads the whole diff in the context of the surrounding files, which is what separates a useful review comment from a linter with better prose. It will tell you that a function you changed has three callers that now break, and it names them.
Where it costs you is private code. Pro is $24 per developer per month, checked 23 August 2026, which for a team of five is $1,440 a year. That is real money for a review layer that sits on top of the human review you are still doing.
The 4.4 across 119 reviews is the most trustworthy number in this comparison. It is not a rave, and the complaints are consistent and predictable: too many comments on large diffs, and a tendency to restate what the code does before saying anything about it.
Sourcery
Sourcery is the value pick, at $12 a month for the Pro tier, half of CodeRabbit's per-seat price, and it has a free tier that works on your own code rather than only on public repos.
It started as a Python refactoring tool and the heritage shows. It is at its best when it spots that a block can be rewritten more simply, and weaker at the architectural observations CodeRabbit reaches for. If your codebase is mostly Python, that trade goes in your favour.
Its 4.8 is the highest rating in this article and rests on 17 reviews, which is not enough to mean anything. Judge it on the free tier, which takes an afternoon to evaluate.
Codacy
Codacy is the enterprise-shaped option: static analysis, coverage tracking, security scanning and AI review in one product, with Pro at $18 a month and an Enterprise tier at $40.
Its free tier covers open source. The reason to choose it over CodeRabbit is not the AI review, which is the weakest of the three, but the fact that it replaces three other tools. If you are already paying for a coverage service and a SAST scanner, the comparison changes shape entirely.
4.4 across 31 reviews, the same score as CodeRabbit on a quarter of the sample.
GitHub Copilot
Copilot is not a code review tool, and it is on this list because its free tier is the most generous thing in the category and because Copilot code review now ships inside pull requests on GitHub.
At $10 a month for Pro it is the cheapest paid tier here by a wide margin, and it does the autocomplete job as well. The review it produces is shallower than CodeRabbit's, and it does not chase callers across files with the same persistence.
The honest framing: if you already pay for Copilot, try its review before buying anything else on this list. You may find it is enough, and the $24 you were about to spend per developer stays in your pocket.
No aggregated rating, which for a product with millions of users tells you the same thing our other guides keep finding. These directories are built for procurement, and Copilot is bought on a company card by individual developers.
Graphite
Graphite is a stacked-pull-request tool that added AI review, not the other way around, and that origin decides who it is for.
If your team already splits work into small dependent PRs, Graphite is the best experience here by some distance, because the review understands the stack. If you open one big PR per feature, most of what you are paying for does nothing.
Hobby is free. Starter is $20 per user per month billed annually, checked 25 August 2026, which puts it between Sourcery and CodeRabbit.
Its 3.8 rating comes from 3 reviews. That is not a rating.
Greptile
Greptile indexes your entire codebase rather than reading diffs, which lets it answer questions no diff-scoped reviewer can: whether the pattern you just introduced already exists elsewhere under a different name.
There is no free tier. $30 per active developer per month is the entry price, and "active" is doing work in that sentence: you pay for developers who opened a PR that month, not for every seat, which makes it cheaper than it looks for teams with a long tail of occasional contributors.
Which to pick
If your code is public, CodeRabbit free is the answer and there is not much to debate.
If your code is private and you want to spend as little as possible, try Copilot's review first, because you may already be paying for it, then Sourcery at $12 if you need something deeper.
If you are consolidating tools rather than adding one, Codacy is the only entry here that replaces things you already buy.
And if a rating tempted you, re-read the review counts. In a category this young they are the number that matters, and four of the six tools here do not have enough of them to argue with.
What an AI reviewer costs when it works
The per-seat prices above understate the real cost in one direction and overstate it in another, and both are worth thinking through.
They understate it because the bill scales with your team while the value does not. CodeRabbit at $24 per developer is $288 a year for one engineer and $2,880 for ten, but the tenth engineer does not get ten times less benefit than the first, they get roughly the same. Tools priced per seat in a category where value is per pull request will always feel expensive at the point you have enough people for it to matter.
Greptile's model is the exception and deserves credit for it. Billing $30 per active developer means a contractor who opened two PRs in March costs you nothing in April. For an open source project with a long tail of drive-by contributors, that is the difference between affordable and absurd.
They overstate it because of what these tools displace. The most expensive thing in code review is not the tool, it is the four hours a senior engineer spends per week reading diffs. If an AI reviewer catches the null dereference and the missing await before a human opens the PR, the human's four hours become three. At any realistic salary that is worth more than $24 a month, and it is the only argument for these tools that survives contact with a finance team.
The failure mode is the opposite one. A reviewer that leaves eleven comments on every PR, nine of them restating what the code does, adds work instead of removing it. This is the single most common complaint in CodeRabbit's 119 reviews and it is not a fixable configuration problem so much as a tuning exercise you have to be willing to do.
Three questions before you buy any of them
Is your code public? If yes, this is a solved problem: take CodeRabbit's free tier and stop reading.
Do you already pay for GitHub Copilot? Then you already have a code reviewer and have probably never turned it on. Do that first. It costs nothing extra and it may end the search.
Do you review in stacks or in one big PR? Graphite is excellent for the first and largely pointless for the second, and no rating on any directory will tell you that.
For more on the tooling around this, see our guides to free CI/CD tools, free error tracking tools and free vibe coding tools.
