Screen Info
Record browser-reported dimensions and capability signals, then calculate panel density separately from entered native specifications.
Go to test controlsThis check runs directly on this page without requiring fullscreen. Review what this browser test can and cannot measure.
Before you start
- Move the browser window to the display you want to inspect.
- Keep track of scaling and browser zoom; obtain the viewable diagonal and native pixel dimensions from the exact model specifications for PPI.
Step-by-step instructions
How to run this check
- Open Screen Info tool
- Move the browser window to the display you want to inspect
- Record the reported CSS screen and viewport dimensions, device-pixel ratio, and color depth
- Treat browser media-query matches as capability signals rather than measured gamut coverage
- Enter the panel diagonal and verified native pixel dimensions to calculate PPI independently of browser zoom
Resolution
Pixel Density
Browser Color Signals
Browser Cadence
Browser Capabilities
Browser
Calculate density from your panel specifications
Find the viewable diagonal and native pixel dimensions in your exact model's specifications. Browser dimensions and zoom do not supply these inputs. This calculation assumes a flat rectangular screen with square pixels.
Enter the panel diagonal and native pixel dimensions to calculate PPI.
Formula: √(native width² + native height²) ÷ diagonal. For example, a 27-inch 3840 × 2160 panel gives about 163.2 PPI and 0.156 mm per pixel. Changing app zoom changes text size, not that pixel density. Use the viewing geometry calculator to compare actual desk positions.
After moving this window to another display, refresh the reported info and confirm the entered diagonal and native pixels belong to that display.
🔧 Technical Details
What each value is—and is not
These values describe the browser's current environment. They are useful when copied with the browser, display, scaling, and window position, but they are not a hardware inventory.
| Value | Source | What it describes | What the browser lacks |
|---|---|---|---|
| CSS screen dimensions | window.screen.width and height | The logical screen coordinate space exposed to this browser window | Native panel pixels, configured signal timing, and the reason scaling was applied |
| Device-pixel ratio | window.devicePixelRatio | The current mapping ratio between CSS pixels and device pixels used by the browser | Physical PPI, native resolution, and a reliable split between OS scaling and browser behavior |
| Calculated PPI estimate | Native pixel dimensions and diagonal you enter from the panel specifications | A formula result for those stated inputs | Verified viewable diagonal and native pixel matrix; confirm both for physical PPI |
| Color-gamut media query | matchMedia('(color-gamut: …)') | A browser/output capability signal for sRGB, P3, or Rec.2020 | Gamut coverage, color accuracy, active HDR output, and a measured display profile |
| Browser cadence | Visible-tab requestAnimationFrame intervals | How often callbacks arrived during this short browser sample | Exact signal rate, panel refresh certification, frame delivery cause, and input latency |
What this browser test can tell you
Can help you check
- CSS pixel dimensions, device-pixel ratio, color depth, and browser media-query signals.
Cannot measure
- Without user input, this test cannot determine physical size, PPI, model, or exact gamut coverage.
Interpret this observation
- Record the reported values together with browser zoom, scaling, browser, and display selection.
- Pixel density is calculated from the diagonal and native pixel dimensions you enter, independently of browser zoom. Confirm those inputs in the model specifications; gamut coverage needs suitable measurement equipment.
Setup and sources
Recommended setup
- Move the browser window to the display you want to inspect.
- Keep browser zoom and operating-system scaling in mind when recording the reported values.
Sources
Methodology reviewed: