Diffy vs Loki

Diffy is a visual regression testing service that captures website pages and compares screenshots to show changes. It can capture pages as logged-in users and test admin pages without requiring code. To help with changing content, users can mock dynamic page elements while checking layout and styles. Diffy detects vertical shifts and provides pixel-perfect comparisons, thumbnails, individual approvals and shareable diff links. AI summaries group changes by type and prioritize them by impact. Listed integrations include GitHub Actions, Jenkins, CircleCI, Playwright, GitHub pull requests, Zapier, Figma, Slack, webhooks and a Claude skills plugin. Local development integrations include DDEV, Lando and Docksal, and an on-premises installation option is listed. The free plan includes 500 screenshots per month, two environments and one month of data retention. Pro costs $67 a month when billed annually and includes 2,000 screenshots per month, multiple environments, CI automation and six months of retention. CI and API access, custom environments and history beyond one month require a paid plan.

Loki is a free, MIT-licensed tool for checking Storybook projects for visual regressions. It captures story screenshots and compares them with reference images, producing visual differences for review. The workflow is to create reference screenshots, run comparisons, review the differences, and approve updated references. Loki is designed for continuous integration, where tests can fail if reference images are missing. Capture targets include Chrome in Docker or locally, Chrome in AWS Lambda, the iOS simulator, and the Android emulator; an AWS Lambda renderer is available for large test suites. Node 16 or later is required. Recent Storybook versions need no extra integration for non-React Native projects, while React Native setup uses an import in `storybook/storybook.js`. Projects can configure Loki in a `package.json` section or supported Loki configuration files. Loki does not start Storybook or simulator and emulator servers, so they need to be running before tests. Documented animation limitations include looping requestAnimationFrame animations, GIFs, SVG animations, native Lottie animations, and React Native Animated.