Best Code Review Tools
Your code review process matters more than the tool—but the right tool helps
By Toolradar Editorial Team · Updated
GitHub/GitLab built-in reviews are sufficient for most teams—master the process before adding tools. Reviewable enhances GitHub with better UX for complex reviews. LinearB and Sleuth provide review analytics if you want to optimize. Focus on review culture and practices before buying specialized tools.
Code review tools are peculiar: the built-in features of GitHub and GitLab are good enough for 95% of teams. Yet some teams still have painful reviews—slow, contentious, or rubber-stamped. The secret? Review quality comes from culture and process, not tools. That said, the right tooling can reinforce good practices and remove friction. Here's how to think about it.
What are Code Review Tools?
Code review tools facilitate peer review of code changes before they're merged. At minimum, they show diffs, enable comments, and track approval status. Advanced tools add automation (linting, security scanning), analytics (review time, bottlenecks), and workflow features (review assignment, stacking). Most teams use their Git hosting platform's built-in reviews.
Why Code Review Matters
Code review catches bugs before production, spreads knowledge across the team, and maintains code quality standards. Good reviews also mentor junior developers and ensure no one works in isolation. The ROI is clear: catching issues in review is 10-100x cheaper than finding them in production. But bad reviews—slow, hostile, or superficial—have negative value.
Key Features to Look For
Clear visualization of code changes with syntax highlighting
Leave feedback directly on specific lines of code
Track approvals, requests for changes, review completion
Show test and lint results in the review context
Automatic or rule-based assignment of reviewers
Propose specific code changes reviewers can accept with one click
Track review time, throughput, and bottlenecks
Review dependent PRs without merge conflicts
Key Factors to Consider
Evaluation Checklist
Pricing Overview
GitHub Free (public repos), GitHub Team $4/user — sufficient for 90%+ of teams
Reviewable ~$10/user, GitLab Premium $29/user — better UX or analytics
GitHub Enterprise $21/user, LinearB custom — compliance, audit logs, SAML
Top Picks
Based on features, user feedback, and value for money.
95% of teams — integrated reviews, GitHub Actions CI, and the largest developer ecosystem
GitHub teams frustrated with large PRs and wanting per-file review tracking
Engineering leaders wanting data on what's slowing down the review process
Mistakes to Avoid
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Blaming the tool when culture is the problem — slow, hostile, or rubber-stamp reviews aren't fixed by better software; they're fixed by team agreements and leadership
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Giant PRs that nobody reviews effectively — research shows review quality drops sharply above 400 lines; break changes into smaller, focused PRs
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Single reviewer bottleneck — if one person reviews everything, they become the constraint; use CODEOWNERS to distribute load across 3+ reviewers
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Treating review as gatekeeping — adversarial reviews slow teams and hurt morale; frame reviews as collaborative improvement, not approval seeking
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Adding specialized tools before mastering basics — if your team doesn't review within 24 hours, Reviewable or LinearB won't fix that
Expert Tips
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Keep PRs under 400 lines — smaller PRs get reviewed 3x faster and catch more bugs; if you can't make it smaller, your abstraction is wrong
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Review within 24 hours — set this as a team SLA; long review queues are the #1 cause of developer frustration and slow delivery
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Use required status checks — GitHub branch protection + Actions CI means broken code can't merge; automate what humans shouldn't have to check
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Authors must provide context — PR description should include: what changed, why, how to test, and areas needing extra attention; reviewers shouldn't have to guess
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Measure review cycle time (LinearB or manual) — most teams discover their biggest pipeline bottleneck is waiting for review, not coding
Red Flags to Watch For
- !No suggested changes feature — reviewers describing fixes in comments instead of proposing exact code edits wastes everyone's time
- !Review analytics are completely absent — you can't improve what you can't measure; at minimum track review cycle time
- !No CODEOWNERS or auto-assignment — manual reviewer assignment creates bottlenecks and uneven workload
- !Platform forces context-switching — if your review tool is separate from your code hosting, you're adding friction to every review
The Bottom Line
GitHub Pull Requests (free to $4/user) are sufficient for 95% of teams — focus on culture (small PRs, fast turnaround, constructive feedback) before adding tools. Reviewable (~$10/user) helps if GitHub's UX is your bottleneck for large PRs. LinearB (free tier + custom pricing) helps if you need data on what's actually slowing down your pipeline. The best review tool is engaged teammates who care about code quality.
Frequently Asked Questions
How big should a pull request be?
Research suggests under 400 lines changed gets better reviews—beyond that, review quality drops sharply. Some teams target under 200 lines. If your PRs are routinely huge, that's your biggest improvement opportunity.
How long should code review take?
Industry benchmarks: first review within 24 hours, total cycle under 48 hours for most PRs. If you're consistently longer, you have a bottleneck—usually too few reviewers or PRs that are too large.
Should we require specific reviewers or let anyone approve?
It depends on code criticality. Core infrastructure might require specific experts. Feature code can often be reviewed by anyone on the team. CODEOWNERS on GitHub helps automate smart defaults.
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