Your screen resolution, pixel ratio, viewport and DPI — detected instantly.
What these numbers mean
- Screen resolution — the physical pixels of your display, e.g. 1920 × 1080 (Full HD) or 2400 × 1080 on a phone.
- CSS resolution — what websites see. Phones and high-DPI laptops report fewer "logical" pixels than physical ones.
- Pixel ratio (DPR) — physical ÷ logical. 2× or 3× on most phones, 1× on basic monitors, 1.25–2× on laptops with scaling.
- Viewport — the size of the browser window area that shows the page.
- PPI / DPI — pixels per inch; enter your screen size to calculate it. Phones are 350–500 PPI; monitors 90–160.
Common resolutions
| Name | Pixels |
|---|
| HD | 1280 × 720 |
| Full HD (1080p) | 1920 × 1080 |
| QHD / 2K | 2560 × 1440 |
| 4K UHD | 3840 × 2160 |
| Typical phone | 1080 × 2400 (FHD+) |
Test the display for faults with the dead pixel test.
How to use the screen resolution checker
- Open the page — your resolution in CSS pixels, the device-pixel ratio and the browser window size appear at once.
- Enter your screen's diagonal in inches to see pixel density (PPI) and the physical size of a pixel.
- Rotate your phone or resize the browser window; the numbers update live.
- Note the values when a support team or web developer asks 'what resolution are you on?'
Resolution, DPR and PPI explained
Your phone may be sold as 1080 × 2400, yet the page reports 360 × 800. Both are right: the physical panel has 1080 × 2400 device pixels, but the browser lays out pages in CSS pixels that are 3 × 3 device pixels each (device-pixel ratio 3), so text stays readable. PPI (pixels per inch) is the sharpness: a 6.5-inch 1080 × 2400 phone has about 405 PPI; a 15.6-inch 1920 × 1080 laptop about 141 PPI; a 24-inch 1080p monitor 92 PPI.
PPI = √(width² + height²) ÷ diagonal inchesCommon Indian device resolutions
| Device | Physical pixels | CSS pixels (typical) | PPI |
|---|
| Budget Android (6.7", HD+) | 720 × 1600 | 360 × 800 @2 | 262 |
| Mid-range Android (6.5", FHD+) | 1080 × 2400 | 360 × 800 @3 | 405 |
| iPhone 15 / 16 | 1179 × 2556 | 393 × 852 @3 | 460 |
| 15.6" laptop | 1920 × 1080 | 1536 × 864 @1.25 | 141 |
| 14" laptop (2.8K OLED) | 2880 × 1800 | 1440 × 900 @2 | 243 |
| 24" office monitor | 1920 × 1080 | 1920 × 1080 @1 | 92 |
| 43" 4K TV | 3840 × 2160 | — | 102 |
Tips and common mistakes
- For photo and signature uploads, the pixel dimensions the portal asks for are device pixels of the image, not your screen — use the Photo & Signature Resizer for Forms.
- Designers: test layouts at 360, 390, 768, 1366 and 1920 CSS pixels wide — that covers 90% of Indian traffic.
- Windows display scaling of 125% is why a 1920 × 1080 laptop reports 1536 × 864.
- Check your panel for defects with the Dead Pixel Test; find a video or image's aspect ratio with the Aspect Ratio Calculator.
Frequently asked questions
Why does my phone show a lower resolution than advertised?
Websites see CSS pixels. Multiply by the pixel ratio (shown above) to get the real physical resolution.
What is DPI vs PPI?
PPI is pixels per inch on a screen; DPI is dots per inch in printing. They're often used interchangeably for screens.
How do I change my screen resolution?
Windows: Settings → System → Display. Mac: System Settings → Displays. Android/iOS resolution is fixed, though some phones offer a power-saving lower mode.