Responsively App
A modified web browser that helps in responsive web development. A web developer's must have dev-tool.
Responsively App 
A must-have dev tool for web developers for quicker responsive web development. 🚀
Save time by becoming 5x faster!
Download Now (free!): responsively.app
#Responsively App
A modified browser built using Electron that helps in responsive web development.
#Features
- Mirrored User-interactions across all devices.
- Customizable preview layout to suit all your needs.
- One handy elements inspector for all devices in preview.
- 30+ built-in device profiles with the option to add custom devices.
- One-click screenshots on all your devices.
- Hot reloading is supported for developers.
Please visit the website to learn more about the application - https://responsively.app
#Download
The application is available for Mac, Windows and Linux platforms. Please download it from responsively.app
Alternatively, MacOS users can use brew
brew install --cask responsively
Also, Windows users can use chocolatey
choco install responsively
or winget:
winget install ResponsivelyApp
Linux users using an RPM Package Manager can use rpm
sudo rpm -i https://github.com/responsively-org/responsively-app/releases/download/v[VERSION]/Responsively-App-[VERSION].x86_64.rpm
otherwise, download an AppImage from the releases page
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#Browser Extension
Install the handy browser extension to easily send links from your browser to the app and preview instantly.
#MCP Server (AI coding agents)
Responsively App ships a built-in Model Context Protocol server, so AI coding agents like Claude Code and Cursor can drive the app while you build — load your dev server, switch device previews, interact with pages, and visually verify responsive layouts with per-device screenshots.
Install the app, launch it once, then connect from Claude Code:
claude mcp add responsively -- npx -y @responsively/mcp
Or add to Cursor's .cursor/mcp.json:
{ "mcpServers": { "responsively": {"command": "npx", "args": ["-y", "@responsively/mcp"]} } }
The app is launched on demand — connecting an agent session doesn't open it; the first tool call starts it automatically (and it stays open afterwards). If it's already running, it's reused.
Available tools:
| Tool | Description |
|---|---|
get_app_state |
Current URL, page title, layout, zoom and active devices |
navigate |
Load a URL in all device previews (waits for the page to load) |
list_devices |
Full device catalog, including custom devices |
set_active_devices |
Change which devices are previewed, by id or name |
screenshot |
Capture one or all device previews as JPEG images |
read_page |
Read a preview's page text and interactive elements with CSS selectors |
click |
Click an element (trusted mouse event; mirrors across previews) |
type_text |
Type into a form field with real keystrokes, optionally press Enter |
Screenshots capture the visible viewport and are downscaled to at most 1000px wide.
Advanced configuration
The app's MCP server listens on http://127.0.0.1:12720/mcp (localhost only) whenever the app is running. If your MCP client can't run npx, connect to it directly — but you'll need to have the app running yourself:
claude mcp add --transport http responsively http://127.0.0.1:12720/mcp
Environment variables understood by @responsively/mcp:
| Variable | Purpose |
|---|---|
RESPONSIVELY_APP_PATH |
Path to a custom app install (auto-detected otherwise) |
RESPONSIVELY_MCP_PORT |
Port of the app's MCP server (default 12720) |
RESPONSIVELY_MCP_BRIDGE |
Direct path to a bridge cli.js (development override) |
Linux note: the app ships as an AppImage, so launch it once before first agent use — that's how the CLI learns where it lives.
#Issues
If you face any problems while using the application, please open an issue here - https://github.com/responsively-org/responsively-app/issues
#Roadmap
Here is the roadmap of the desktop app - https://github.com/responsively-org/responsively-app/projects/
#Gold sponsors 🥇
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Become a sponsor and have your company logo here
#Contribute
To get started with contributing your awesome ideas to Responsively, follow the comprehensive guide here!
#Get in touch
Come say hi to us on Discord! :wave:
#Contributors ✨
Thanks go to these wonderful people (emoji key):
This project follows the all-contributors specification. Contributions of any kind are welcome!