What is the difference between physical and CSS resolution?

Physical resolution is the actual number of pixels on the screen panel. CSS resolution is what the browser use for layout. On high-DPI screens (like Retina), several physical pixels are used to render one CSS pixel for sharpness.

How do I check my monitor aspect ratio?

This tool automatically calculates your aspect ratio by finding the greatest common divisor of your width and height. For example, 1920x1080 is 16:9.

Screen Resolution Checker — Detect Display Size & PPI Online

Screen Resolution Checker — Display Size & PPI Detector

📅Published: February 21, 2026👤Author: FPS Tools Team

Instantly check your screen resolution, pixel density (PPI), device pixel ratio, aspect ratio, and more. No downloads required.

Detecting your display information...

What Is Screen Resolution?

Screen resolution describes the number of pixels your display uses to render images, expressed as width × height (e.g., 1920×1080). More pixels mean sharper detail, finer text, and more screen real estate for applications.

Modern displays range from HD (1366×768) on budget laptops to 4K (3840×2160) on high-end monitors and 8K (7680×4320) on professional displays. For gaming, 1080p and 1440p remain the most popular resolutions due to the balance between visual quality and GPU performance requirements.

Understanding Device Pixel Ratio (DPR)

Device Pixel Ratio is the relationship between CSS pixels (what the browser uses for layout) and physical device pixels. A DPR of 2 means each CSS pixel is rendered using 2×2 = 4 physical pixels, resulting in sharper text and images on Retina/HiDPI displays.

Resolution and Gaming Performance

Higher resolutions require significantly more GPU power. Moving from 1080p to 1440p increases pixel count by 78%, and moving to 4K increases it by 300%. If your FPS is low, reducing resolution is one of the most effective ways to improve performance.

Frequently Asked Questions

Why does my resolution show differently than expected?

Your browser may be using display scaling (e.g., 150% on Windows). The resolution shown here is the CSS resolution, which may differ from your native panel resolution due to OS-level scaling.

What resolution is best for gaming?

1080p (1920×1080) remains the most popular for competitive gaming due to lower GPU requirements and higher achievable FPS. 1440p (2560×1440) offers a great balance for enthusiasts, while 4K is reserved for those with high-end GPUs.