CSS viewport 211 × 257 pixels at 2× device pixel ratio. The exact size browsers report on the Apple Watch Ultra 3.
The Apple Watch Ultra 3 viewport is 211 × 257 CSS pixels, with a device pixel ratio of 2 on a 422 × 514 pixel 49 mm display. Estimated from physical resolution ÷ default DPR; the browser-reported value may differ by a few pixels.
Test your site at Apple Watch Ultra 3 (211 × 257)
When a user visits your site on the Apple Watch Ultra 3, the browser reports window.innerWidth = 211 and window.devicePixelRatio = 2. Your CSS media queries match against the 211px CSS width, not the 422 × 514 physical pixel count of the panel.
At 211px it hits no Tailwind breakpoint (base styles only) and no Bootstrap breakpoint.
For sharp full-width images, serve a source at least 422px wide (211 CSS px × 2 DPR) through srcset and let the browser pick it.
/* Apple Watch Ultra 3: 211×257 CSS px, DPR 2 */
@media (max-width: 211px) {
/* styles for this width and narrower */
}
@media (min-resolution: 2dppx) {
/* serve high-density assets */
}The Apple Watch Ultra 3 reports a CSS viewport of 211×257 pixels. This value is derived from the physical resolution divided by the default device pixel ratio. Browser toolbars reduce the visible height slightly, so window.innerHeight is usually smaller than the full screen height.
The Apple Watch Ultra 3 uses a default device pixel ratio of 2. Each CSS pixel maps to 2×2 physical pixels on its 422×514 panel.
At 211px wide it matches no Tailwind breakpoint and no Bootstrap breakpoint, so only your base (mobile-first) styles apply.
Open screensize.io, enter your URL and pick Apple Watch Ultra 3 (211×257). It opens your site in a real browser window at exactly that CSS viewport, so media queries, container queries and JavaScript resize logic behave as they would on the device. For touch behaviour and the real browser engine, confirm on hardware before shipping.
See the full list of device viewport sizes →
Or browse common screen sizes by category →
Use screensize.io to preview your website at any of these resolutions instantly — no DevTools needed.
Open screensize.io →