Frontend Regression Validator vs Loki
Frontend Regression Validator
github.com
Loki
loki.js.orgSide by side
| Figure | Frontend Regression Validator | Loki |
|---|---|---|
| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | Yes | Yes |
| Windows | — | Yes |
| macOS | Yes | Yes |
| Linux | Yes | Yes |
| iOS | — | Yes |
| Android | — | Yes |
| API | Yes | — |
| Self-hosted | Yes | Yes |
| Plans published | 1 | 1 |
| Spec score · Visual Regression Testing Software | 8.1 (#7) | 8.6 (#4) |
| License | The repository includes an Apache License 2.0, which grants no-charge, royalty-free rights subject to its terms. | The project repository identifies Loki as MIT licensed. |
| Purpose | FRED is an open-source visual regression tool for automatically comparing baseline and updated website instances. | Loki tests Storybook projects for visual regressions by comparing screenshots with reference images. |
Plans
In their own words
Frontend Regression Validator
Frontend Regression Validator has no write-up on Specifiction yet; its figures are above.
Loki
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.