---
title: "Screen Resolution Detector"
description: "Instantly detect your screen resolution, viewport size, device pixel ratio, color depth, and orientation. Browser-based tool with no downloads required."
url: https://findutils.com/network/screen-resolution-detector/
category: network
---

# Screen Resolution Detector

Instantly detect your screen resolution, viewport size, device pixel ratio, color depth, and orientation. Browser-based tool with no downloads required.

**Use this tool:** [Screen Resolution Detector](https://findutils.com/network/screen-resolution-detector/)

## Programmatic access

- Browser-only: this tool works on a file, the DOM, or a browser API and has no REST or MCP id.

## Why Use Screen Resolution Detector?

Screen Resolution Detector helps developers and designers understand display characteristics across different devices. Whether you're testing responsive designs, optimizing images for different pixel densities, or debugging viewport issues, this tool provides instant access to essential screen information including resolution, pixel ratio, and touch support detection.

## Tips for Accurate Detection

- Maximize your browser window before checking resolution to get the full viewport measurement.
- On laptops with Retina or HiDPI screens, the logical resolution will be lower than the physical pixel count -- multiply by the pixel ratio.
- Browser zoom level (Ctrl +/-) changes the reported viewport size but not the screen resolution.
- Connect an external monitor and open the tool on that display to check its resolution independently.
- Use the detected viewport size to choose the correct CSS breakpoint for your responsive design.

## Frequently Asked Questions

### What is device pixel ratio?

Device pixel ratio (DPR) is the ratio between physical pixels and CSS pixels. A DPR of 2 means each CSS pixel is rendered using 4 physical pixels (2x2), common on Retina displays.

### Why is viewport size different from screen resolution?

Screen resolution is your monitor's total pixel count, while viewport size is the visible area in your browser window, which changes when you resize the window or browser UI takes up space.

### What does color depth mean?

Color depth indicates the number of bits used to represent each pixel's color. 24-bit means 8 bits per color channel (RGB), allowing for 16.7 million colors.

### Why does my phone show a lower resolution than expected?

Phones report logical resolution (CSS pixels) rather than physical pixels. Multiply by the device pixel ratio to get actual physical resolution.

### How can I use this for responsive design?

Use the viewport size to test breakpoints, check DPR for image optimization (serve higher resolution images for high DPR screens), and verify touch support for interaction patterns.

### Does this tool require a signup?

No. The Screen Resolution Detector is available with no signup, no usage limits. Detection runs entirely in your browser -- nothing is uploaded to a server.

### Does browser zoom affect the results?

Browser zoom changes the reported viewport size and can alter the effective device pixel ratio, but it does not change the underlying screen resolution. Reset zoom to 100% for the most accurate viewport reading.

### Can I check the resolution of an external monitor?

Yes. Drag the browser window to the external monitor and refresh the page or click the refresh button. The tool will report the resolution and pixel ratio of whichever display the browser window is currently on.

### What is effective physical resolution?

Effective physical resolution is your logical screen resolution multiplied by the device pixel ratio. For example, a 1440x900 display with a DPR of 2 has an effective physical resolution of 2880x1800 pixels.

### Does this work on mobile devices?

Yes. The tool works in any modern mobile browser and reports the device's logical resolution, viewport size, pixel ratio, orientation, and whether touch input is supported.

## Related Tools

- [Aspect Ratio Calculator](https://findutils.com/calculate/aspect-ratio-calculator/)
- [Image Resizer](https://findutils.com/convert/image-resizer/)
- [Social Media Image Resizer](https://findutils.com/convert/social-media-image-resizer/)
- [Contrast Checker](https://findutils.com/design/contrast-checker/)
- [Color Converter](https://findutils.com/design/color-converter/)
- [Image Compressor](https://findutils.com/convert/image-compressor/)
- [Placeholder Image Generator](https://findutils.com/generate/placeholder-image-generator/)
- [Favicon Generator](https://findutils.com/design/favicon-generator/)