Code review checklist generator
Pick your language and review categories, get a tailored markdown checklist you can paste straight into a PR template. Free, runs entirely in your browser.
## Code Review Checklist ### Correctness - [ ] The change does what the PR description says it does - [ ] Edge cases are handled (empty input, null/undefined, zero, max sizes) - [ ] Error paths are handled, not swallowed silently - [ ] Concurrency: no race conditions on shared state - [ ] Off-by-one errors checked in loops, slicing, and pagination ### Security - [ ] All user input is validated server-side - [ ] No secrets, tokens, or credentials in code or logs - [ ] SQL/NoSQL queries are parameterized, never string-concatenated - [ ] Output is encoded/escaped where rendered (XSS) - [ ] Authorization is checked at the resource level, not just authentication - [ ] New dependencies reviewed for maintenance status and known CVEs ### Tests - [ ] New behavior has tests; changed behavior has updated tests - [ ] Tests cover the failure path, not just the happy path - [ ] Tests fail when the implementation is broken (not tautological) - [ ] No flaky patterns: real timers mocked, no order dependence ### TypeScript / JavaScript specifics - [ ] No `any` types introduced without justification - [ ] Promises are awaited or explicitly handled (no floating promises) - [ ] `useEffect` dependencies are complete and intentional - [ ] Bundle impact considered for new client-side dependencies > Generated with the free [Code Review Checklist Generator](https://diffwise.app/tools/code-review-checklist-generator) by Diffwise.
Why use a code review checklist?
Reviewer attention is a budget. Without a written list, the same reviewer who catches a SQL injection on Monday morning waves through an unparameterized query on Friday afternoon. The well-known SmartBear study of code review at Cisco found reviewers using checklists caught significantly more defects, and that detection drops sharply past about 400 lines of code per session.
A checklist also depersonalizes feedback. "Item 4: error paths handled" lands better than "I wouldn't do it this way", and juniors learn the team's standards by reading the list instead of by being surprised in comments.
How to use the generated checklist
- Pick your language and the categories that match the PR type. A docs change does not need the performance section.
- Copy the markdown and paste it into your pull request description, your
PULL_REQUEST_TEMPLATE.md, or your team wiki. - Prune quarterly. Items that have not caught anything real in six months get cut or automated.
The strongest checklist items come from your own postmortems. If a missing timeout caused last quarter's outage, "every outbound call has a timeout" goes on the list and stays.
Automate the mechanical half
Roughly half the items on any review checklist are pattern checks a machine can run: injection risks, N+1 queries, missing error handling, leaked secrets. Formatters and linters cover the syntax-level items; an AI reviewer like Diffwise covers the contextual ones with 40+ specialist agents on every PR, so your human reviewers only work through the judgment items: authorization design, abstractions, edge-case reasoning.
For the full reasoning behind every item in this generator, read The Code Review Checklist Every Team Needs in 2026.
Frequently asked questions
Is this code review checklist generator free?
Yes, completely free with no signup. The checklist is generated in your browser; nothing is sent to a server.
How many items should a code review checklist have?
Under 40 total and under 10 per category. Past that, reviewers skim instead of check. Cut anything your formatter, linter, or AI reviewer already enforces.
Where should I put the checklist?
A short version (5-8 highest-value items) in your PULL_REQUEST_TEMPLATE.md as task-list checkboxes, and the full version linked from your contributing guide.
Can I automate these checks instead of running them by hand?
Most pattern-level items, yes. Formatters and linters handle style and known syntax bugs; AI code reviewers like Diffwise handle contextual patterns such as injection risks, N+1 queries, and missing error handling on every pull request automatically.