Updated November 2026

Best code review tools: the platform, the checks and the AI

For most teams, the best code review tool is the pull request review already built into their Git host: GitHub, GitLab or Bitbucket. Add Gerrit or Review Board if you need patch-by-patch or self-hosted review, SonarQube for rule-based checks, Graphite for stacked changes, and an AI reviewer such as CodeRabbit or IonWarp for a first pass.

Published by Winding AI, Inc., the company that makes IonWarp, one of the ten tools here. IonWarp only does one of the jobs below, on GitHub only, and we say where others fit better. Prices were read from each vendor's page on 7 November 2026.

Code review happens in three layers

• Layer 1Where people reviewThe pull request in your Git host, or a review server such as Gerrit. Every team needs exactly one.
• Layer 2What machines checkStatic analysis and quality gates such as SonarQube. The same rules on every change.
• Layer 3Who reads firstAn AI reviewer that comments before a person does. Optional, newest, and the noisiest.

Many "best code review tools" lists mix the layers and compare GitHub with SonarQube as if you'd pick one. You pick one tool for layer 1, then add layers 2 and 3 if they earn their keep. Workflow tools such as Graphite sit on top of layer 1.

Start with the review in your Git host

Pull requests (merge requests on GitLab) are where most code review happens: a diff, line comments, suggested changes, approvals and a merge button. The catch on all three big hosts is that the controls that make review mandatory sit on a paid tier.

GitHub

Free organizations get unlimited private repositories and pull requests, but branch protection on private repos (required reviewers, code owners) needs a paid plan. Team costs $4 per user a month and adds draft PRs and multiple reviewers. Enterprise is $21 per user and now includes access to Copilot, with usage billed separately.

GitLab

Free covers 5 users per top-level group on GitLab.com. Merge request approval rules start at Premium, $29 per user a month billed annually, which includes $12 a month of GitLab Credits per user for AI features such as code review. GitLab also runs self-managed.

Bitbucket

Free for up to 5 users with unlimited private repos. Standard is $3.65 per user a month; Premium, $8, is the tier that enforces merge checks. The natural pick if your team lives in Jira.

Azure DevOps

Microsoft's Azure Repos has its own pull requests, and GitHub Copilot code review is sold for it, billed in GitHub AI Credits.

When a separate review server is worth it

Standalone review tools predate pull requests and still win in a few places: very large codebases, strict pre-merge control, non-Git version control, or code that must stay on your own servers.

Gerrit

Each commit is a change, reviewed as a series of patchsets until it's approved and before it reaches a branch. Fine-grained permissions, a REST API and 100+ community plugins. Free and open source (current release 3.14.5); the cost is running it yourself.

Review Board

Reviews code, images and documents, and works with Git, Jujutsu, Perforce, Subversion, Mercurial, ClearCase, Azure DevOps and even CVS. Open source; the paid Power Pack adds enterprise integrations and reports, and RBCommons hosts it from $6 per user a month (30-day trial).

Phorge

The community-maintained fork of Phabricator, which has been unmaintained since 1 June 2021. It keeps Differential's pre-push review and post-push audits, so it's the low-effort path for teams still on Phabricator.

Crucible and Upsource: retired

Atlassian stopped selling Fisheye and Crucible on 13 May 2025 and ends support on 15 May 2028; if you run Crucible, plan the move now. Older lists still recommend JetBrains Upsource, whose product page now redirects to JetBrains' home page.

Stacked pull requests: Graphite

Stacking splits a big change into small pull requests that depend on each other, so each one is quick to review and they merge in order. Graphite adds a stacking CLI, a PR inbox, a merge queue and an AI reviewer on top of GitHub. Hobby is free for personal repos; Starter, at $20 per user a month billed annually, covers organization repos; Team, $40, adds unlimited AI reviews and the merge queue. GitHub only.

Automated checks: static analysis

Rule-based analysers report the same finding for the same code every time, which makes them the right thing to make a required check.

• SonarQube prices by lines of code, not seats: free for private projects up to 50,000 lines, Team from $34 a month for 100,000, Enterprise by quote. The Community Build is open source for self-hosting, and public OSI-licensed repos are free. GitHub, GitLab, Bitbucket and Azure DevOps.
• Codacy Team is $18 per developer a month yearly ($21 monthly) for up to 30 developers and 100 private repos, with an AI reviewer and merge gates. Cloud GitHub, GitLab and Bitbucket only: no Azure Repos and no self-hosted Git.
• DeepSource, now part of Harness, is $24 per user a month billed yearly, with $100 a year of AI review credit per user. It works with all four hosts and self-hosts on Enterprise.

AI reviewers: a first reader, not an approver

AI reviewers read each diff and comment before a person does. They catch logic slips no rule covers, but they also miss things and add noise. On Martian's independent tracker, which scores whether a bot's suggestions led to code changes on real open-source pull requests, Greptile scores 65.2% F1, Qodo 62.3%, CodeRabbit 61.0% and GitHub Copilot 60.6%. In IonWarp's own benchmark, run by the company behind this page on 50 pull requests from Martian's open benchmark (not certified by Martian), Qodo has the highest F1 (58.5%), above IonWarp (56.6% on its best model, 49.2% on its default). The tool that caught the most, Qodo, still found only 62% of the known issues.

• CodeRabbit reviews on GitHub, GitLab, Bitbucket and Azure DevOps, for $24 per developer a month on annual billing. The safe pick off GitHub.
• GitHub Copilot code review comes with Copilot Pro ($10 a month) and Business ($19 per user). By default its review is a comment that doesn't count toward required approvals.
• IonWarp (ours) runs Code Review on every GitHub PR and adds specialist reviewers, such as security, cost, docs or SOC 2, when a diff needs them. Which ones depends on the plan: free Starter has Code and Security Review, and SOC 2 Review comes with Max. One workspace price covers seats and a monthly pool of review credits: $49 a month for 5 people against $120 for CodeRabbit. It is GitHub only, can't be self-hosted and isn't on Martian's tracker.

Qodo, Greptile, Cursor Bugbot, Sourcery, Bito and the open-source PR-Agent are also worth a look; IonWarp keeps a longer comparison of AI reviewers.

See IonWarp's plans

How to choose

1. Where does the code live? That picks layer 1 and rules tools out: Graphite and IonWarp need GitHub; Codacy skips Azure Repos.
2. Must it run on your servers? Look at Gerrit, Review Board, Phorge, GitLab Self-Managed, SonarQube's Community Build, and the enterprise tiers of AI reviewers.
3. Which rules must be enforced? Required approvals, code owners and merge checks are paid features on every big host; price the tier that has them.
4. Is review slow because changes are big? Smaller or stacked pull requests fix more than any bot.
5. What's repetitive? Automate it: formatters and linters in CI, static analysis as a gate, an AI reviewer as a first pass.

Questions people ask

What is the best code review tool?

For most teams, the pull request review in GitHub, GitLab or Bitbucket. Choose Gerrit for strict patch-by-patch review, Review Board for Perforce or Subversion, and Graphite for stacked pull requests on GitHub. Then add SonarQube or Codacy for automated checks and, if you want one, an AI reviewer for a first pass.

What tools are used for code review?

Three kinds: a place to review (Git host pull requests, Gerrit, Review Board, Phorge), automated checks (linters, SonarQube, Codacy, DeepSource) and AI reviewers (CodeRabbit, Qodo, Greptile, GitHub Copilot, IonWarp and others).

Is GitHub a code review tool?

Yes. Pull requests are GitHub's review tool and are free with unlimited private repositories. Required reviewers and code owners on private repositories need a paid plan; for organizations that starts with GitHub Team, $4 per user a month.

What replaced Phabricator?

Phorge, a community-maintained fork; Phabricator itself has been unmaintained since 1 June 2021. Teams leaving that model altogether can move to GitHub or GitLab pull requests, or to Gerrit for a similar pre-merge flow.

Is Atlassian Crucible still available?

Not to new customers. Atlassian stopped selling Fisheye and Crucible on 13 May 2025 and ends support and maintenance on 15 May 2028.

What is the difference between code review and static analysis?

Static analysis runs fixed rules and reports the same findings every time. Code review is a person, or an AI reviewer, reading a change for logic, design and intent. Make static analysis a required check and keep review for what rules can't see.

Are there free code review tools?

Yes: GitHub pull requests, GitLab Free (5 users per group), Bitbucket (up to 5 users), the open-source Gerrit, Review Board and Phorge, SonarQube's free tier up to 50,000 lines, and IonWarp's Starter plan for 3 seats on GitHub.

Should an AI reviewer approve pull requests?

Usually not. In IonWarp's benchmark the tool that caught the most still missed 38% of the known issues. GitHub Copilot's reviews don't count toward required approvals unless an admin turns that on; leave the approval to a person.

About this page

Published by Winding AI, Inc., the company that makes IonWarp. IonWarp is one AI reviewer among the ten tools here, and most of this page is about tools we don't make. Every price was read from the vendor's own page on 7 November 2026 and links there. Accuracy figures come from Martian's independent tracker and from IonWarp's own benchmark, labelled as ours. There are no star ratings, scores of our own or testimonials, and no vendor paid to be listed. Spot a price that has changed? Email support@winding.ai. For more on the review process itself, IonWarp has a guide to pull request review.