Vesper Mosaic

Vesper Mosaic is a macOS desktop application for responsive QA. It loads one URL into three side-by-side panes at mobile (390), tablet (768), and desktop (1920) widths simultaneously, with anchor-element scroll sync, click-and-navigation sync, and a shared session across all three panes.

It exists to replace bloated stand-alone responsive-QA tools with one focused app that does exactly what daily auditing workflows need - and nothing more. No device profiles, no plugins, no per-pane toolbars.

Getting started

• Quick Start - Install Vesper Mosaic, load your first URL, and learn the three view modes.

Reference

• Viewport Modes - How Fit and 100% modes scale and lay out the three panes.
• Sync Behavior - Anchor-element scroll sync, click sync, navigation sync, back/forward, and the shared session partition.
• Cache & DevTools - Purging the shared HTTP cache and opening DevTools for each pane.

Help

• Troubleshooting - Notarization warning on first launch, DPR not emulated, and other known limitations.

Releases

• Release Notes - What's new in each version of Vesper Mosaic.