Mergeao .
Compare reference designs against implementation screenshots without uploading source files.
Overview
Mergeao is a local-first visual comparison workspace for designers and developers. It helps teams inspect visual drift between an approved design and the current implementation, review iterations and export evidence without sending source images to a remote service.
Features
- Slider, side-by-side, onion skin, Blink and pixel/perceptual diff modes
- Batch comparison with difference percentages and CSV export
- Local browser processing with a privacy-first file model
- PWA offline shell and image, HTML, CSV and animation exports
- CLI/CI package and GitHub snapshot workflow for repeatable checks
Architecture & decisions
The app is built with React, TypeScript and Vite, with Web Workers keeping larger image comparisons responsive. A reusable @mergeao/core package powers CLI and CI checks, while Vitest and Playwright cover the comparison engine, exports, accessibility and end-to-end flows.
Project note
The source repository is private, while the public product website is available for exploring the current experience and capabilities.