Sizzy

Sizzy provides a dedicated web‑development browser that lets users view and interact with a site on several device frames simultaneously. It includes built‑in tools for visual debugging, synchronized scrolling between views, and quick style inspection, allowing developers and designers to spot layout or CSS issues without switching between multiple tabs or external emulators. The environment is positioned as a single workspace where testing, debugging, and presentation of responsive designs can be performed in parallel.

The software targets web developers, front‑end engineers, and UX/UI designers who need to verify how their pages render across different screen sizes and conditions. By consolidating device simulations, style editing, and bug‑investigation features, it aims to reduce context‑switching and accelerate the workflow for responsive‑design work.

Sizzy runs on macOS in a stable release, is actively maintained, and emphasizes privacy and security. It offers a free trial and has addressed recent installation issues on Windows 11, though the primary platform remains macOS.