Simulate code review workflows with feedback, inline comments, and approval states. Part of the DevTools Surf developer suite. Browse more tools in the DevOps / CI-CD collection.
Use Cases
Practice receiving code review feedback before joining a team
Generate review checklists for different code types (API endpoints, database migrations, auth flows)
Train junior developers on what quality code review looks like
Simulate security-focused review to identify common vulnerability patterns
Tips
Paste a git diff or code snippet and select the review type (security, performance, style, logic) to focus comments on specific concerns
Use the 'reviewer persona' selector to simulate feedback from different perspectives: backend engineer, security auditor, or junior developer
The inline comment mode annotates specific lines — export as a structured review for pasting into GitHub PR review interface
Fun Facts
Code review as a formal engineering practice was pioneered by Michael Fagan at IBM in 1976 through 'Fagan Inspection' — a highly structured review process that studies showed could find 60-90% of bugs before testing.
A 2015 study by SmartBear found that reviewers who look at more than 400 lines of code per hour miss significantly more defects than those reviewing at slower rates. The sweet spot for effective review is 200-400 lines per hour.
Google's 'Readability' process requires all code to be approved by a designated 'readability reviewer' for the language before it can be merged. Engineers earn readability certification by demonstrating deep knowledge of the style guide — a program unique to Google's engineering culture.
FAQ
How many reviewers should review a pull request?
Research suggests 1-2 reviewers for most code changes. Adding more reviewers beyond 2 has diminishing returns for bug detection and increases coordination cost. For critical systems or security-sensitive changes, 2-3 reviewers is appropriate.
What should code review focus on?
Priority: correctness (does it do what it claims?), security (does it introduce vulnerabilities?), maintainability (is it readable?). Style should be caught by automated linters, not reviewers — humans are better used for logical and architectural concerns.
How long should a code review take?
The SmartBear study found effective reviews take 30-90 minutes for changes under 400 lines. Larger PRs should be split. If review takes more than 2 hours, the PR is too large.
