Loki review
A free Storybook screenshot tool for web, iOS, and Android visual checks.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Loki is an open-source command-line tool for visual regression testing in Storybook projects. It captures screenshots of Storybook stories, compares them with stored reference images, generates image differences, and supports approval or updating of reference images. Its targets include web through Chrome, iOS simulators, and Android emulators, making it a focused option for teams working across web and mobile interfaces. Loki is distributed as a development dependency under the MIT license, with a free open-source plan.
For visual comparison, Loki supports pixelmatch, GraphicsMagick, and looks-same diffing engines. Chrome capture can run in Docker, AWS Lambda, or a local Chrome application, giving teams several execution options for development and continuous integration workflows. The tool also supports React and React Native alongside Storybook, which fits projects where component stories span browser and native application targets. Its approval workflow helps teams manage updated reference images as visual changes are reviewed.
Loki is a strong fit for Storybook teams that want a free, code-oriented visual regression workflow with mobile simulator and emulator targets. It is less suitable for teams that need cross-browser capture, AI-assisted analysis, or a broader platform with features beyond Storybook-centered screenshot comparison. The command-line and development-dependency model also favors engineering-led teams comfortable incorporating visual checks into project and CI workflows.
Loki pros and cons
- Where it wins
- Free and open source under the MIT license
- Supports Storybook, iOS simulators, and Android emulators
- Includes CI checks and reference-image approval workflows
- Where it doesn't
- Does not provide cross-browser capture
- Requires project setup as a development dependency
- No AI-assisted features
Loki fact sheet, pricing and score →
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