Responsively App is a modified web browser designed specifically for web developers who need to test and debug responsive websites across multiple screen sizes without switching between tabs or devices. Built with Electron, it provides a unified interface that displays your website on 30+ pre-configured device profiles simultaneously, allowing real-time inspection and interaction. Unlike traditional browser dev tools that only simulate one viewport at a time, Responsively App mirrors user interactions across all displayed devices and offers synchronized scrolling, element inspection, and one-click screenshots. This tool eliminates the repetitive workflow of manually resizing windows or using mobile emulators, making it indispensable for developers building responsive web applications.
Targeted at frontend developers, UI/UX designers, and QA engineers working on responsive websites or web apps, Responsively App reduces the time spent on cross-device testing by up to 80%. It supports macOS, Windows, and Linux via native installers or package managers like Homebrew, Chocolatey, and Winget. The app also includes a browser extension to instantly send any URL from Chrome, Firefox, or Edge directly into the app for immediate previewing.
What You Get
- Mirrored user interactions across all devices - Clicks, scrolls, and form inputs are synchronized across every device view in real time, ensuring consistent behavior testing without manual repetition.
- Customizable preview layouts - Arrange device previews in grid configurations that suit your workflow, from side-by-side mobile and desktop views to multi-row layouts for complex breakpoints.
- Unified elements inspector - Inspect HTML/CSS/JS elements from any device view using a single inspector panel that updates dynamically based on the selected preview.
- 30+ built-in device profiles - Pre-configured screen sizes for popular phones, tablets, and desktop resolutions including iPhone 15 Pro, iPad Pro, Samsung Galaxy S23, and MacBook Pro.
- One-click screenshots of all devices - Capture a full set of device previews with a single click, ideal for client demos or bug reports.
- Hot reloading support - Automatically refreshes the preview when you save changes in your code, eliminating manual reloads during development.
- Browser extension integration - Install the Responsively Helper extension for Chrome, Firefox, or Edge to instantly send any webpage URL directly into the app with one click.
Common Use Cases
- Building a multi-tenant SaaS dashboard with responsive layouts - Developers test how complex data tables and navigation menus render across mobile, tablet, and desktop views simultaneously to ensure usability for all user segments.
- Creating a mobile-first e-commerce platform with 10k+ SKUs - Designers validate product card layouts, image scaling, and CTA button placement across 50+ device profiles to prevent layout breaks on obscure screen sizes.
- Problem: Manual browser resizing slows down testing → Solution: Responsively App displays all breakpoints at once with synchronized interactions - Instead of toggling between Chrome’s device mode, Safari’s responsive design mode, and physical devices, developers preview everything in one window with real-time interaction mirroring.
- DevOps teams managing cross-browser responsive sites - Teams use the app to validate responsive behavior across platforms before deployment, reducing support tickets from users on non-standard devices.
Under The Hood
The Responsively app is a comprehensive desktop and browser extension-based tool designed to aid responsive web development by providing real-time previewing, device simulation, and cross-browser consistency checking. It leverages modern web technologies to deliver an integrated solution for developers working on responsive designs.
Architecture
The application adopts a layered architecture that clearly separates concerns between the main Electron process, renderer components, and utility modules. This modular design enables maintainable code organization and scalable development.
- The architecture distinguishes between the main process (Electron), renderer (React), and utility modules, supporting a clean separation of responsibilities
- Component communication is managed through Redux-based state management and event-driven patterns, enhancing UI logic modularity
- Design patterns such as observer for pubsub systems, strategy in device handling, and factory patterns in webview operations are consistently applied
- The codebase is organized into distinct functional modules, including menu handling, permissions, and screenshot management, ensuring clear boundaries
Tech Stack
The project utilizes a modern JavaScript/TypeScript ecosystem tailored for Electron-based desktop applications and browser extensions. It integrates various tools and frameworks to support a full-featured development environment.
- Built primarily in TypeScript with React for the frontend, using Electron for cross-platform desktop functionality and Webpack for module bundling
- Relies on a suite of libraries including Electron, React with Material-UI, browser-sync, and Redux for state management
- Development tools include Webpack 4/5, Electron Builder, Babel, ESLint, and Prettier for consistent code formatting and build processes
- Testing infrastructure incorporates Jest, TestCafe, React Testing Library, and Enzyme to ensure component and integration reliability
Code Quality
The codebase reflects a mixed quality profile with strengths in testing and error handling, although some inconsistencies and technical debt remain. The overall structure supports automation but could benefit from more uniform conventions.
- A comprehensive testing framework is in place with unit, integration, and end-to-end test coverage across components and workflows
- Error handling is implemented through standard try/catch patterns and custom error messages, though some implementations show inconsistency
- Code style is generally consistent with adherence to linting and formatting standards, though some modules exhibit signs of technical debt
- The codebase demonstrates moderate consistency in naming conventions and architectural patterns, supporting readability and maintainability
What Makes It Unique
Responsively App distinguishes itself through its unique combination of desktop and browser extension capabilities, offering a seamless experience for responsive web testing. Its approach to device simulation and previewing sets it apart in the developer tool space.
- The modular architecture allows for independent development and deployment of desktop app logic versus browser extension functionality, enhancing flexibility
- Innovative use of Electron’s webview API enables sandboxed device previewing with custom context menus and granular permission controls
- The application features an extensive device list management system that supports user-defined preview suites with customizable configurations
- Screenshot capture and webview storage are implemented in a way that ensures cross-platform rendering consistency, a key differentiator in responsive testing tools