Test screen resolution.
An online utility to instantly detect physical and logical monitor dimensions, viewport size, device pixel ratio (DPR), and color depth. Perform dead pixel checks, gamut calibration, and motion response tests in one click.
Display Parameters
Real-time parameters detected directly from your web browser sandbox.
The actual hardware pixel grid of your monitor.
The logical resolution used by CSS and browsers to render elements.
Current dimensions of the browser window. Try resizing the window!
Scale factor between physical hardware pixels and logical CSS pixels.
Number of bits used to represent color for each physical pixel.
The number of times per second (Hz) your screen redraws the image.
Interactive Diagnostic Tests
Test your display for manufacturing defects, color gamut, color depth banding, and panel response times.
Dead Pixel Detector
Dead pixels are defective sub-pixels that remain permanently black, white, or stuck on a specific color. This test displays full-screen solid primary colors. By cycling through them, you can easily spot dark specks on bright backgrounds or glowing dots on dark backgrounds.
Color Cycling Diagnostics
Understanding Your Screen
A technical breakdown of why logical viewport resolutions differ from physical manufacturer specifications.
Logical vs. Physical Pixels
Your operating system and browser render elements using Logical (CSS) Pixels to maintain consistent text sizing. Physical Pixels are the actual microscopic physical light-emitting diodes (OLED or sub-pixels) built into your hardware. For high-density displays (such as Apple Retina or Samsung AMOLED), multiple physical pixels are merged to represent a single CSS pixel.
Device Pixel Ratio (DPR)
DPR represents the multiplier scale. If your screen has a DPR of 2.0, a 1x1 CSS box contains exactly 2x2 (4) physical pixels. A DPR of 3.0 means 9 physical pixels form a single logical pixel. This prevents text and layouts from appearing extremely small on modern high-resolution smartphones and laptops.
Refresh Rate & V-Sync
The refresh rate of a screen, measured in Hertz (Hz), is the frequency with which it updates the displayed image. Standard screens operate at 60Hz. High-end gaming monitors or modern mobile panels support 120Hz, 144Hz, or 240Hz, offering significantly smoother motion transitions. The motion test lane measures actual render loop speeds and flags ghosting effects.
Color Depth (Bit-Depth)
Color depth defines the range of colors a screen can project. An 8-bit panel can display 16.7 million variations (TrueColor), whereas a professional 10-bit panel supports 1.07 billion colors. Displays with limited bit depths or poor calibration often display noticeable vertical "bands" inside our smooth gradients.
Comprehensive Guide to Screen Resolution & Diagnostics
When configuring a digital display, understanding your display properties is critical. Many users search online asking, what is my screen resolution or what's my screen resolution? Knowing these figures is key to selecting wallpapers, optimizing gaming performance, setting up multi-monitor configurations, and testing mobile application layouts.
What is Screen Resolution?
At its core, screen resolution is the total number of distinct pixels in each dimension that a display device can show. It is formatted as width × height (such as 1920 × 1080). The higher the resolution, the sharper and more detailed images and text appear. Over the years, standard screen resolution sizes have transitioned from legacy analog formats like VGA (640 × 480) and SVGA (800 × 600) to modern digital benchmarks. Today, standard displays range from High-Definition (HD or 720p) and Full HD (FHD or 1080p) to Quad HD (QHD or 1440p) and Ultra HD (UHD or 4K/8K). Conducting a web-based screen resolution test is the easiest way to inspect your system's current dimensions without navigating settings menus.
Logical Viewports vs. Hardware Resolutions
Modern consumer hardware can cause confusion because physical specifications and CSS rendering dimensions differ. For example, looking at a modern mobile layout like the iphone screen resolution shows a hardware spec of 1170 × 2532 physical pixels, but the browser treats the viewport as 390 × 844 logical pixels. This discrepancy is managed by the Device Pixel Ratio (DPR). High-density screens (like Retina and AMOLED) use a multiplier (such as 2.0 or 3.0) to group physical hardware pixels to render a single logical CSS pixel. This scaling mechanism ensures that icons, text, and layout parameters remain comfortable to read, rather than shrinking to micro-scale dimensions on high-density screens.
How to Check Screen Resolution in Windows and macOS
If you need to query your operating system settings directly, learning how to check screen resolution is a simple process:
- On Microsoft Windows: Right-click on an empty area of your desktop and select Display settings. Scroll down to the Scale and layout header and look under the Display resolution selector to identify your current resolution.
- On Apple macOS: Click the Apple menu icon at the top-left of the screen and navigate to System Settings. Select Displays from the sidebar. You will see a list of scaled layout options, with the active configuration highlighted.
While manual checking works, our automated browser inspection tool detects these parameters instantly upon page load, displaying viewport dimensions, aspect ratios, and color depths in real-time.
How to Change Screen Resolution
Knowing how to change screen resolution is important when you want to customize your desktop layout, increase text scaling for readability, or adjust rendering loads:
- On Windows: Navigate to Settings > System > Display. Click the dropdown menu next to Display resolution and select from the available options. Click Keep changes when prompted to confirm the configuration.
- On macOS: In the Displays panel under System Settings, click one of the scaled thumbnail icons. Choosing a resolution that says "Larger Text" decreases the logical resolution (scaling up elements), whereas selecting "More Space" increases the logical resolution (shrinking elements to fit more items on the screen).
It is recommended to run your display at its native resolution (marked as "Recommended" in Windows). Running scaled resolutions can result in pixel interpolation, causing text to look slightly soft or blurry.
Running Monitor Diagnostics
This utility does more than detect specifications—it helps diagnose panel health:
- Dead Pixel Inspection: Stuck or dead pixels are manufacturing defects. By cycling through solid colors (Red, Green, Blue, White, Black) in fullscreen, you can inspect the screen to verify every sub-pixel is lighting up correctly.
- Color Calibrations & Banding: Testing smooth gradient bands shows whether your screen supports high color depths (such as 10-bit HDR) or exhibits stepped banding lines.
- Refresh Rate & Motion Clarity: High-performance screens (120Hz+) render animations smoothly. Our high-precision canvas motion test runs at the monitor's native refresh rate, letting you check for frame drops, stutters, and trailing ghosting issues.
Frequently Asked Questions
What is my screen resolution?
Your screen resolution is the dimensions of your display measured in horizontal and vertical pixels. You can instantly view your active screen resolution, viewport size, and device pixel ratio (DPR) at the top dashboard on this page.
How to change screen resolution?
On Windows: Right-click the desktop, click 'Display settings', open the 'Display resolution' dropdown, select your desired resolution, and click 'Keep changes'. On macOS: Navigate to Apple Menu > System Settings > Displays, and select from the scaled thumbnail size presets.
What is screen resolution?
Screen resolution represents the total width and height of a display screen expressed in pixels (e.g., 1920x1080). Higher resolutions package more pixels together, creating a sharper, more detailed image and allowing more content to fit on the screen.
What resolution is my screen?
Your screen's resolution can be checked immediately by looking at the real-time statistics panel on our homepage. It inspects your web browser's window properties to determine both logical CSS and physical display pixel sizes.
How to find screen resolution?
You can find your screen resolution by checking your OS Display Settings (in Windows desktop settings, or the Displays tab in macOS System Preferences), or by loading a web utility like testscreenresolution.com for an instantaneous diagnostic check.
How do you measure screen resolution?
Screen resolution is measured by the quantity of horizontal and vertical pixels (Width x Height). For instance, Full HD measures 1920 pixels wide by 1080 pixels high. It is also measured in pixel density, which is defined as Pixels Per Inch (PPI).
What resolution is 1920x1080?
A resolution of 1920x1080 is called Full HD (FHD) or 1080p. It is a standard widescreen format featuring a 16:9 aspect ratio and contains approximately 2.07 million individual pixels.
What screen size is 1024x768?
A screen resolution of 1024x768 pixels represents the XGA (Extended Graphics Array) standard. It is a classic 4:3 square aspect ratio layout, commonly found on older computer monitors and legacy tablets.
Is 1920x1080 4K or HD?
A resolution of 1920x1080 is HD (specifically Full HD/1080p). It is not 4K. True 4K resolution is much larger, featuring 3840x2160 pixels, which packages four times as many pixels as standard 1080p Full HD.
What is HD resolution?
HD (High Definition) resolution natively refers to 1280x720 pixels (720p). Over time, HD has become a general label representing high-density screens including Full HD (1920x1080) and Quad HD (2560x1440).
Is 720p a 16:9 resolution?
Yes, 720p is a 16:9 aspect ratio resolution. It represents a grid of 1280 pixels horizontally and 720 pixels vertically, which conforms exactly to modern widescreen media scaling formats.