Screen Resolution Size Detector

Instantly check screen resolution, viewport size, device info and test responsive layouts with one click.

About Screen Resolution Size Detector Screen Resolution Size Detector is a simple but powerful tool that helps developers, designers, testers, and everyday users see detailed information about their screen, browser, and device — instantly. No more using websites or DevTools just to check your resolution. Open the extension and everything appears in one clean dashboard. Whether you're building responsive websites, testing UI layouts, comparing breakpoints, or switching between desktop and mobile previews, this extension gives you the tools you need in seconds. What This Extension Shows ✔ Screen Resolution (full device resolution) ✔ Viewport Size (actual available browser area) ✔ Device Pixel Ratio (DPR) ✔ Orientation (portrait / landscape) ✔ Color Depth ✔ Browser + OS detection (clean, simplified version — not full User Agent spam) ✔ Platform & Language All information updates instantly with the Refresh Info button. # Responsive Testing Tools Quickly test your webpage in popular screen sizes: Desktop Presets 1920 × 1080 1440 × 900 1366 × 768 1280 × 720 These presets resize your browser window to match the selected desktop resolution. Mobile / iPhone Simulation iPhone (414 × 896) Mobile (375 × 812) Instead of resizing your whole browser, the extension opens a sleek device simulator overlay that displays your current webpage inside a realistic mobile frame. This allows you to test mobile layouts without losing your window size. Includes: - Auto-scaling so the device always fits the screen - Close button to return to normal view - Accurate viewport dimensions inside the device frame # Why Install This Extension? ✔ No need to open DevTools for simple screen checks ✔ No need to visit websites like “What is my screen resolution” ✔ Perfect for designers testing UI responsiveness ✔ Perfect for developers debugging breakpoints ✔ Great for QA testers doing multi-device testing ✔ Clean interface, fast load, and no data collection This extension is built with performance and accuracy in mind — everything runs locally on your browser. # Privacy & Permissions This extension does not collect or store any personal data. Permissions used: *activeTab — to detect your current tab for viewport info *scripting — to safely run read-only scripts on the current page *windows — required to resize the browser window for desktop presets *tabs — needed to open new tabs (welcome page, website links) All actions occur locally and no information is transmitted anywhere. # Optional Website Tools Enhance your experience with the official tool: 👉 https://whatismyscreenresolution.info Includes advanced calculators: - PPI Calculator - DPI Checker - Aspect Ratio Finder - Browser Info Tool - More tools coming soon. # Updates & Improvements - We continuously update: - Device presets - Simulator scaling accuracy - Platform detection - UI improvements Suggestions are always welcome!