If you have ever asked "what is my screen resolution," this tool gives you a clear, accurate answer in seconds. Your screen resolution is the number of pixels your display uses to draw everything you see, and this checker reads it directly from your browser, then breaks it down into the numbers that actually matter for design, testing, and everyday curiosity. Instead of guessing or digging through system settings, you get a live, trustworthy snapshot of your display the moment the page loads.
What the screen resolution checker shows
Most simple tools report a single figure, but a modern display is described by several. Here is what each readout means and how to read it:
- CSS resolution is what web pages and your operating system work in after display scaling. It is the number most "what is my screen resolution" answers actually report.
- Physical resolution is the true pixel count of the panel itself, the figure printed on the spec sheet when you bought the device.
- Device pixel ratio connects the two. A ratio of 1 means one CSS pixel equals one physical pixel; a ratio of 2 is a typical high-density or Retina screen; fractional values like 1.25 or 1.5 come from Windows scaling. Physical resolution equals CSS resolution multiplied by this ratio.
- Color depth is the number of bits used per pixel, which controls how many distinct colors your display can render.
- Aspect ratio is the proportional relationship between width and height, such as 16:9 for most monitors or taller ratios on phones.
Because the readout updates live, you can resize the window or change your browser zoom and watch every value respond, which makes it easy to understand how scaling reshapes the numbers. When the answer to "what is my screen resolution" looks lower than expected, the device pixel ratio almost always explains the difference.
Screen resolution sizes and common devices
It helps to know where you land among standard screen resolution sizes. Full HD, or 1080p, is 1920 by 1080 and remains the most common desktop figure. QHD or 1440p is 2560 by 1440, while 4K UHD reaches 3840 by 2160 and 5K stretches to 5120 by 2880. Comparing your panel against these named tiers tells you at a glance whether you are running a mainstream, high-resolution, or ultra-high-resolution display, and it makes shopping for a new monitor far less confusing.
Mobile devices behave a little differently because of aggressive scaling. If you check an iphone screen resolution, the physical panel might be 1170 by 2532 pixels, yet the CSS resolution your apps and websites see is far smaller because the device pixel ratio is 3. That gap is exactly why a single number can be misleading, and why seeing both the physical and CSS figures matters when you are testing layouts across phones, tablets, and laptops. The same logic applies to Android handsets and high-density tablets, where the marketing resolution and the resolution your code receives rarely match.
Why your screen resolution matters
Knowing your resolution is practical, not just trivia. Designers & developers use it to confirm that a layout looks right at the viewport sizes real visitors have. Gamers and video editors care about it because higher resolutions demand more from a graphics card and storage. Anyone buying a monitor or sharing their setup can use these figures to compare hardware honestly. Whether your goal is troubleshooting a blurry display, calibrating a design, verifying a screenshot, or simply answering "what is my screen resolution" with confidence, this checker gives you every relevant number in one place, read straight from your own browser and yours to copy or export whenever you need it.