---
title: "Screen Resolution Detector - Check Screen Size, Viewport and DPR | CanDoYa"
description: "Free screen resolution detector. See your screen size, viewport, device pixel ratio, orientation, color depth and browser display facts locally."
url: https://candoya.com/tools/screen-resolution-detector/
locale: en
type: browser-tool
---

# Screen Resolution Detector

Category: Developer

## What is a screen resolution detector?

A screen resolution detector reads the display facts your browser can see: screen width and height, available screen area, current viewport size, device pixel ratio, estimated physical pixels, orientation, color depth, touch support and media-query capabilities. This tool shows those values instantly in your browser without uploading anything.

The numbers update when you resize the browser, rotate the device, change zoom or move the window between displays. Screen size tells you the CSS-pixel size reported by the display, viewport size tells you the space available to the web page, and device pixel ratio explains how many physical pixels map to one CSS pixel. Together they help you debug responsive layouts, screenshots, media queries and display-specific bugs.

## Expert note

Browsers report screen and viewport measurements in CSS pixels, not always raw hardware pixels. Device pixel ratio estimates the mapping to physical pixels, but browser zoom, OS scaling and external-display settings can change the relationship. For layout debugging, the viewport size and media-query results are usually the most actionable values because they are what CSS uses.

## Frequently asked questions

### Is this screen resolution detector free?

Yes. It is free to use, with no sign-up and no usage limit.

### Does it upload my screen information?

No. The detector only reads browser APIs on your device. Nothing is uploaded or stored on a server.

### What is the difference between screen size and viewport size?

Screen size is the display size reported by the browser. Viewport size is the area the web page can currently use inside the browser window, so it changes when you resize the window, open sidebars or rotate a phone.

### What is device pixel ratio?

Device pixel ratio, often shortened to DPR, is how many physical display pixels are used for one CSS pixel. Browser zoom, OS scaling and external displays can change it.

## Related tools

- [URL Parser](https://candoya.com/tools/url-parser/)
- [Query String Parser](https://candoya.com/tools/query-string-parser/)
- [Clipboard Inspector](https://candoya.com/tools/clipboard-inspector/)
- [CSS Clamp Calculator](https://candoya.com/tools/css-clamp-calculator/)
- [Color Contrast Checker](https://candoya.com/tools/color-contrast-checker/)

---

*Markdown edition of <https://candoya.com/tools/screen-resolution-detector/>, published for AI agents and other automated readers. Index of key pages: <https://candoya.com/llms.txt>.*