A screen resolution and DPI checker helps you understand your display's pixel count, density, and scaling. Whether you are designing responsive layouts, choosing a monitor, or troubleshooting display issues, knowing your exact screen specs is essential. This tool auto-detects your display properties or lets you enter them manually.
Screen Detection
Your Display
Compare with Common Displays
| Device / Standard | Resolution | Ratio | PPI | DPR |
|---|
How to Use the Screen Resolution & DPI Checker
Understanding your screen resolution and pixel density is important for web development, graphic design, and choosing the right monitor. This tool auto-detects your current display properties or lets you enter specs manually to calculate PPI and compare against common devices.
Step 1: Auto-Detect Your Screen
Click the Auto-Detect My Screen button. The tool reads your display width, height, and device pixel ratio using the browser's Screen API. If your OS uses display scaling (common on 4K monitors and laptops), the tool shows both your CSS resolution and the calculated hardware pixel count.
Step 2: Enter Your Screen Size for PPI
To calculate PPI (pixels per inch), enter your screen's diagonal size in inches. This is the measurement from one corner to the opposite corner. Common sizes include 13.3" for ultrabooks, 15.6" for standard laptops, 24" for desktop monitors, and 27" for larger displays. The tool uses the formula PPI = sqrt(width^2 + height^2) / diagonal.
Step 3: Read Your Display Stats
The results panel shows your resolution, aspect ratio, total pixel count, megapixels, device pixel ratio, and PPI. The Retina/HiDPI badge indicates whether your display has a pixel ratio of 2 or higher, meaning each logical pixel is rendered with multiple hardware pixels for sharper detail.
Step 4: Compare with Common Devices
The comparison table below lists popular displays from 1080p monitors to 5K iMacs, plus mobile devices like iPhones and iPads. If you ran auto-detect, your screen appears highlighted in the table so you can see exactly where it stands. This is useful when deciding on a monitor upgrade or checking if your design targets match real-world screen resolution distributions.
Understanding Device Pixel Ratio
Device pixel ratio (DPR) is the ratio between hardware pixels and CSS pixels. A DPR of 1 means each CSS pixel maps to exactly one physical pixel. A DPR of 2 (common on Retina displays) means each CSS pixel is rendered as 2x2 physical pixels, resulting in four times the pixel data. Web developers use DPR to serve appropriately sized images — a 2x image for Retina screens prevents blurriness.
Frequently Asked Questions
Is this screen resolution checker free?
Yes, this tool is completely free with no account or signup required. All detection and calculations run instantly in your browser, and no data is sent to any server.
Is my data private when using this tool?
Absolutely. Everything runs locally in your browser using the standard Screen API. No screen information, dimensions, or results are transmitted, stored, or logged anywhere.
What is the difference between resolution and PPI?
Resolution is the total number of pixels on your screen (e.g., 1920x1080). PPI (pixels per inch) measures how densely those pixels are packed, which depends on both resolution and physical screen size. Higher PPI means sharper text and images.
What is device pixel ratio (DPR)?
Device pixel ratio is the ratio between physical hardware pixels and CSS/logical pixels. A DPR of 2 means each CSS pixel is rendered using a 2x2 block of hardware pixels. Retina and HiDPI displays typically have a DPR of 2 or higher.
How do I find my screen's PPI?
Click the auto-detect button to get your resolution, then enter your screen's diagonal size in inches. The tool calculates PPI using the formula: PPI = sqrt(width squared + height squared) divided by diagonal inches.
What resolution does a Retina display have?
Retina is not a specific resolution but a marketing term by Apple for displays with a device pixel ratio of 2 or higher. This means the display has enough pixel density that individual pixels are not visible at normal viewing distance.
Why does my detected resolution differ from my monitor's native resolution?
Your operating system may be using display scaling. For example, a 4K monitor at 200% scaling reports 1920x1080 CSS pixels. The tool shows both your CSS resolution and the hardware pixel count when scaling is detected.