What The Diff
AI pull-request assistant that explains GitHub and GitLab diffs and supports code refactoring.
About What The Diff
What The Diff is an AI code review assistant for GitHub and GitLab pull requests. It reads the diff through the repository platform API and posts a descriptive comment that explains the changes in plain English or another supported language. This gives reviewers a quick orientation before they inspect the code themselves, while support for nearly all programming languages makes it usable across mixed repositories. The service also supports code refactoring: the Free plan includes inline refactoring, while the Pro – 200k plan lists instant refactoring. Teams on the paid plan can route activity through Slack, webhook, and email notifications. What The Diff says it does not store source code or pull-request diffs and does not use them to train its AI model. Adoption still involves granting full code access because GitHub and GitLab do not offer a permission limited to reading pull-request diffs. Usage is token-based, so large diffs consume more of the monthly allowance, unused tokens do not roll over, and teams that exhaust their balance must upgrade or wait for the next billing cycle.
Best for
Best use cases
A reviewer opens a pull request and uses the generated description to orient the code review.
A repository receives changes in different programming languages and needs consistent diff explanations.
A paid team routes pull-request activity into Slack, webhook, or email notification workflows.
Compare before choosing
The Free plan includes 25,000 monthly tokens and is rate limited, while Pro – 200k includes 200,000 tokens.
Inline code refactoring is listed for Free, while instant code refactoring is listed for Pro – 200k.
Pro – 200k adds Slack, webhook, and email notifications plus priority email support.
Features
Pull-request explanations
Generates a plain-language description from a GitHub or GitLab pull-request diff.
Code refactoring
Offers inline refactoring on Free and instant code refactoring on Pro – 200k.
Review notifications
Routes Pro activity through Slack, webhook, and email notifications.
Pros
- Supports GitHub and GitLab, making it usable across teams that work on either repository platform.
- Explains diffs in plain English or another supported language across nearly all programming languages.
- States that source code and pull-request diffs are not stored or used to train the AI model.
Cons
- Requires full code access because the repository platforms do not provide a diff-only permission.
- Monthly tokens do not roll over, so unused allowance is lost at the end of each billing cycle.
- The Free plan is rate limited and capped at 25,000 tokens, or roughly 10 average pull requests.
Pricing Plans
Free
- 25,000 tokens per month (~10 PRs)
- Unlimited repositories
- Inline code refactoring
- Rate limited
- No credit card required
Pro – 200k
- 200,000 tokens per month (~40 PRs)
- Unlimited repositories
- Instant code refactoring
- Slack, Webhook and Email notifications
- Priority email support
* Pricing information is for reference only. Please refer to the latest announcement on What The Diff's official website.