About this project

Responsively App is a modified web browser built using Electron, designed to help web developers test responsive layouts more efficiently. The app is available for macOS, Windows, and Linux, with installation options including Homebrew, Chocolatey, winget, RPM packages, and AppImage releases. Core features include: - Mirrored user interactions across all device previews simultaneously, so clicks, scrolls, and typing are replicated across every visible device. - A customizable preview layout that can be adjusted to suit different testing needs. - A single elements inspector that works across all devices in the preview. - Over 30 built-in device profiles, with the ability to add custom device configurations. - One-click screenshot capture across all devices at once. - Hot reloading support for development workflows. A browser extension is available for Chrome, Firefox, and Edge, allowing users to send links from their regular browser directly into the Responsively App for instant preview. The app includes a built-in Model Context Protocol (MCP) server, enabling AI coding agents such as Claude Code and Cursor to programmatically control the application. Through the MCP integration, agents can load URLs across device previews, switch active devices, capture per-device screenshots, read page content and interactive elements, click elements (with mirrored interactions), and type text into form fields. The MCP server listens on localhost port 12720 and launches the app on demand when the first tool call is made. Configuration can be done via npx or by connecting directly to the HTTP transport endpoint. The project is open source and accepts community contributions, with a public roadmap and active Discord community.