Screen Resolution Tester
Automatically measure your monitor resolution and window size.
A free display info tool perfect for web development and settings checks.
🖥️ Your Display Info
This tool runs completely in your browser. Your display information is never sent to or stored on our servers.
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About Screen Resolution Tester
The Screen Resolution Tester is a free online tool that instantly measures and displays your current PC or smartphone screen resolution, browser window size (viewport), device pixel ratio (DPR), and color depth.
It's highly useful for web designers checking responsive layouts or anyone seeking remote technical support who needs to quickly find out their screen dimensions simply by opening a webpage.
All measurement processing occurs entirely within your local browser environment. This means no device data is ever transmitted to external servers, guaranteeing a completely safe and private experience.
How to Use
Access the Page
Simply open this page, and the tool will automatically detect your device and browser settings. No manual start buttons are required.
Check Your Specs
Your screen resolution, current window size, and device pixel ratio will be displayed in the upper panel. You can easily note these numbers if needed.
Resize Your Window
Try resizing your browser window; you will see the "Window Size" values update in real-time to reflect the exact current dimensions.
Display & Resolution Glossary
- Screen Resolution
- The physical or logical number of pixels (width × height) of the entire display. Common examples include Full HD (1920×1080) and 4K (3840×2160).
- Viewport (Window Size)
- The actual area where your browser is currently rendering the webpage. This refers to the pure viewing space, excluding the bookmark bar, scroll bars, etc.
- Device Pixel Ratio (DPR)
- The ratio that indicates how many physical screen pixels are used to draw a single CSS pixel. High-density monitors, such as Retina displays, often have values like 2.0 or 3.0.
- Color Depth
- The number of distinct colors a display can show simultaneously, expressed in bits. Most modern generic displays support 24-bit full color (approx. 16.7 million colors).
- Aspect Ratio
- The proportional relationship between the width and height of a screen. While "16:9" is standard for TVs and PC monitors, vertical ratios are increasingly common for smartphones.
Frequently Asked Questions
- Q.What is the difference between Screen Resolution and Window Size?
- Screen resolution is the size of your "entire monitor screen". Window size, on the other hand, is the size of the "frame where the browser displays the page". Unless your browser is in full-screen mode, the window size will be smaller than the screen resolution.
- Q.Why is the displayed resolution smaller than my monitor's actual specs?
- This is usually due to the OS "Display Scaling" settings (e.g., 125% or 150% in Windows, or "Larger Text" on Mac). The browser retrieves the "logical resolution" which accounts for this scaling, resulting in a smaller value than the physical pixel count.
- Q.Can I measure accurately on smartphones?
- Yes, it works perfectly on smartphones and tablets. If you rotate your device (between portrait and landscape), you will notice the screen resolution and window size updating in real-time.
- Q.What is Device Pixel Ratio (DPR)?
- It is a feature on high-resolution monitors (like Apple's Retina displays) designed to render sharper text and images. A DPR of 2 means a standard-sized image is drawn with twice the density horizontally and vertically (four times the area).
- Q.Will my information be leaked externally?
- No, it will not be sent anywhere. This tool operates entirely within your browser using JavaScript. There is absolutely no functionality included to send or save your measured values to any server.
Use Cases
Checking Display Settings
Useful for confirming that the resolution on a newly purchased monitor or PC is set correctly, or checking if your screen is unintentionally zoomed in.
Web Development & Debugging
Web designers and engineers use it to adjust their window size precisely to match responsive design breakpoints (the widths at which layouts switch).
Image Asset Sizing
When creating full-screen wallpapers or background images for your PC, you can determine the exact screen resolution to ensure the perfect fit.
Assisting Remote Support
When receiving technical support and asked, "What is your screen resolution?", simply opening this page provides you with the exact numbers to share.
Send Feedback
Please let us know your thoughts to help us improve the tool.
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