AI Code Review Tools in 2026: 5 Options Compared (Free Included)
AI code review went from a demo joke to a default part of the pull-request workflow in about two years, and in 2026 the interesting question is no longer whether a bot should read your diff — it is which bot, and what it costs when the free tier ends. This covers five tools a real developer can start with today — three with genuinely usable free tiers rather than fourteen-day trials wearing a free costume. Every price and limit below was read from the vendors own pricing pages on October 19, 2026 — and the honest answer to "which one?" depends on exactly one thing: whether your code is public or private.
The 30-second answer
If your repositories are public: CodeRabbit is the strongest free option — reviews are free forever on public repos, with the paid plan at $24 per developer per month billed annually. If your code is private and you want to pay nothing: Greptile's free plan (50 credits per month, one developer, unlimited repos) or Sourcery's free plan are the realistic starts, and Sonar's AI code review is free forever for open-source projects with feature parity to its paid team plan. If you already pay for GitHub Copilot Pro at $10 per month, its native code review is the cheapest upgrade you will never see on a separate bill — and if you are shopping for your team rather than yourself, the per-seat math matters more than any individual feature, because these tools differ far more in pricing model than in review quality.
What "AI code review" actually means in 2026
Three different products wear the same label; mixing them up is how people get disappointed with the category. First, platform-native review: GitHub Copilot reviews pull requests inside github.com itself, with no third party holding your code — the same trust model as the rest of your GitHub data. Second, review bots: CodeRabbit, Qodo, and Greptile install on your repositories as an app or GitHub Action, comment line by line on every pull request, and answer follow-up questions in the thread. Third, linter-descendants: Sourcery and Sonar grew out of static analysis and add AI explanations and fix suggestions on top. All three styles catch bugs; they differ in how much they intrude and where your code goes while they think.
The five tools, honestly compared
1. GitHub Copilot code review — the platform-native one
Copilot's code review runs on github.com, on any pull request, including from users who do not pay for Copilot — if the organization allows it. The plans page is specific: Copilot Free is $0 but limited to 2,000 completions and 50 chat requests per month and does not include code review; review starts at the Pro plan, $10 per month, and also ships in Pro+ ($39) and Max ($100). Two details hide in the fine print and both matter. Code review consumes AI Credits and Actions minutes, so heavy use is metered even on a paid plan. And an organization administrator can enable Copilot code review for members without a Copilot license — that usage is billed to the organization, which makes Copilot a legitimate team-wide review layer without buying everyone a seat, if someone watches the Actions bill.
2. CodeRabbit — the free king of public repos
CodeRabbit is the most established dedicated review bot, and its pricing page states the deal plainly: free reviews forever for public repositories. On private repos you move to the Essentials plan — the page notes this plan keeps the former Pro price of $30 per developer per month, or $24 when billed annually. For context: that is the most expensive paid option here, which funds the free open-source tier. The product reviews diffs line by line, learns your codebase conventions over time, and answers questions in the pull-request thread. If you maintain open-source projects, there is no rational reason not to have it installed.
3. Qodo — the trial, honestly labeled
Qodo (whose merge agent grew out of PR-Agent) has the most honest pricing page in the category: no permanent free tier for private repos, and it says so. What you get is a 14-day trial with no credit card, then credit-based plans — the trial tiers on the page list roughly 18 reviews per month at 2,500 credits and about 36 at 5,000 — and, importantly, a free plan for open-source projects through the Qodo for Open Source program. Its differentiator is generated tests: it reviews your pull request and writes the unit tests the diff implies. Choose it if test coverage is the actual hole in your workflow; skip it if you wanted a permanently free private-repo bot, because this one is not pretending to be that.
4. Greptile — the free tier with a real ceiling
Greptile's Starter plan is the most generous genuinely-free private-repo option here: free, with 50 credits per month, one active developer, and unlimited repositories, plus a free tier for qualified open-source projects. The paid Pro plan is $30 per seat per month with extra credits at $1 each. The word to fix in your head is credits — each review action consumes them, so 50 credits is a light monthly cadence: roughly a review a day, not a review a minute. Greptile's pitch is codebase-aware review that reads your whole repository for context rather than just the diff. For a solo developer pushing a few pull requests a week to private repos, the free tier is genuinely enough; for a busy team, the credits meter is where the bill shock lives.
5. Sourcery — the linter descendant with a permanent free plan
Sourcery started as a Python refactoring linter and evolved into a GitHub/GitLab review tool with a two-minute install and a free plan that stays free. Its open-source projects are free outright, and the paid tiers are the second-cheapest here: Pro at $12 per seat per month and Team at $24, both billed annually. Sourcery is the most opinionated of the five — it enforces consistent style and flags constructs it considers risky, which makes it the best fit for teams that keep arguing about the same patterns in review comments. Do not expect architecture-level commentary; expect your future self to stop writing the same loop badly.
The comparison table
| Copilot code review | CodeRabbit | Qodo | Greptile | Sourcery |
|---|
| Free tier (verified 2026-10-19) | Free plan has completions+chat (2,000/50 per month) but NO code review; review starts at Pro | Free forever on public repos | Open-source program free; 14-day trial otherwise; no permanent free tier for private repos | Starter: free, 50 credits/mo, 1 dev, unlimited repos | Free plan (permanent); open source free |
| Paid entry price | Pro $10/mo (includes review) | Essentials $24/dev/mo billed annually ($30 monthly) | Credit-based plans; page does not list a permanent entry free tier | Pro $30/seat/mo; extra credits $1 each | Pro $12/seat/mo; Team $24/seat/mo (annual) |
| Where it reviews | Native on github.com PRs | Bot comments on GitHub/GitLab PRs | Bot + generated tests on GitHub/GitLab | Codebase-aware bot on GitHub | Bot on GitHub/GitLab; IDE plugins |
| Metering model | AI Credits + Actions minutes | Per developer per month | Credits per review | Credits per review | Per seat per month |
| Best for | Teams already paying for Copilot; org-wide review without per-seat licenses | Public/open-source repos | Teams needing tests + review together | Solo devs, private repos, zero budget | Style consistency; Python-heavy codebases |
| Where it hurts | Review locked out of the Free plan; metered credits | Most expensive paid tier | No free private-repo home | 50 free credits run out fast | Opinionated; shallower architectural review |
From my own workflow: when one of these bots flags a diff and I want an agent to actually act on it — run the suite, apply the fix — I dispatch from the terminal with AgentDelegator CLI, the small tool we build and use daily. It costs $5, one-time (price re-verified on Gumroad, October 19, 2026). It is not a code reviewer; it is the dispatch layer between a review comment and a running agent.
AgentDelegator CLI — $5 on Gumroad
Affiliate disclosure: this is our own product and the link is an affiliate link; we earn a commission if you buy, at no extra cost to you.
The free-tier math, where free actually ends
Read the table as a ladder. Zero dollars gets you: public-repo reviews (CodeRabbit, Sourcery, Sonar's open-source offering, and Greptile's qualified OSS tier), a light private-repo cadence (Greptile's 50 credits, Sourcery's free plan), or Copilot's completions and chat — but not its reviews. The first real payment in this category is either $10 (Copilot Pro, if review is the point) or nothing at all if your repositories are public. The trap is not the sticker price; it is metering. Credits-per-review pricing (Qodo, Greptile) and credits-plus-Actions-minutes pricing (Copilot) both convert a busy sprint into an unpredictable invoice. Per-seat pricing (CodeRabbit, Sourcery) is boring and predictable, which is a feature.
Two honorable mentions outside the five: Sonar's Gitar AI Code Review is free forever for public, open-source-licensed repos with feature parity to the paid team plan (and SonarQube's team plan is free for private projects up to 50,000 lines) — if your stack is already Sonar-based, start there. Graphite also has a free hobby tier for personal repos.
Who it's NOT for
This comparison is not for you if your organization forbids third-party bots from reading your code — for regulated or security-sensitive codebases, platform-native review (Copilot on GitHub, where the code already lives) is the only category that clears most procurement reviews, and read GitHub's data-handling terms first. It is not for you if you wanted an autonomous senior engineer: none of these tools merges anything, and all five will occasionally suggest the wrong refactor — a human still approves. It is not for you if your team already argues productively in review comments. And if you are a solo developer on private repos who cannot spend money this month, start with Greptile's free tier or Sourcery's free plan and skip the free tiers that are trials in disguise.
How this was compared — and what was not done
Honesty section. Every number in this article was read from the vendors own pricing pages on October 19, 2026 — and re-read, not remembered. What was NOT done: no controlled benchmark trials, and no accuracy scoring against a labeled bug dataset, because nobody publishes one. The honest claim is narrower: this desk runs several of these tools daily on its own code. Find a number that drifted? Email us and we will re-fetch and fix it the same day.
The honest verdict
For public repositories the answer is almost boring: install CodeRabbit (free forever) and Sourcery (free plan) and keep the one whose comments you actually read — two free bots reviewing one pull request is a reasonable configuration. For private repositories with zero budget, Greptile's 50 free credits per month is the only serious private-repo tier in this list, with Sourcery's free plan as the style-focused second pair of eyes. For developers already paying for Copilot Pro, native code review is included — there is nothing else to buy. And for teams: buy the predictable per-seat tool, not the credits tool, unless your sprint volume is genuinely low. In 2026, AI review is table stakes, the free tiers are real, and the only expensive mistake is a credits meter running loose on a busy repository.
Questions, corrections, or a pricing change I missed? Email nandminc2020@gmail.com and I will re-fetch the live pages and update the post.
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