Two kinds of number
Everything on this site is either sourced or computed, and the distinction matters.
Sourced figures come from a primary publisher: manufacturer specifications for devices, official documentation for framework breakpoints, platform help pages for image dimensions, ISO 216 for paper sizes. These carry a verification date.
Computed figures are derived arithmetically from sourced ones — aspect ratios, megapixel counts, column widths, unit conversions, pixel dimensions at a given DPI. These cannot drift out of sync with the data they come from, because they are generated at build time and never typed by hand.
Device data
Each device record stores the logical (CSS) viewport in portrait, the native panel resolution, the device pixel ratio, the manufacturer-stated pixel density and the screen diagonal.
As a consistency check, the build recomputes pixel density from the panel resolution and the diagonal — √(w² + h²) ÷ diagonal — and compares it against the manufacturer figure. A deviation above 3% fails the build. This catches transposed digits and wrong resolutions, which is the most common way a device table goes bad.
Where scale × logical width does not equal the physical width, the panel renders downsampled. That is a real property of certain devices — the iPhone 6/7/8 Plus and the 12/13 mini among them — and is labelled as such rather than silently corrected.
Aspect ratios
Ratios are reduced to their exact integer form using the greatest common divisor. A ratio is only labelled with a common name such as 16:9 when it is within 1% of that value; otherwise the exact form or a decimal approximation is shown. A 1668 × 2420 iPad panel is reported as 417:605, not rounded to something tidier.
Unit conversions
CSS conversions follow the CSS Values and Units specification, which fixes 1in at exactly 96px. These are exact for CSS and are not physical measurements — a CSS inch on a 460 PPI phone is nothing like an inch of glass. Print conversions use real DPI instead and are handled separately under print sizes.
Freshness
Verification dates on this site are the date the underlying source was actually checked — never the date the page was rebuilt. A page rebuilt today showing data verified in August 2026 says exactly that. Social platform dimensions change most often and carry the most visible date stamp.
Known limitations
- Android is fragmented. Viewport values are for the stock browser at default display settings; manufacturer skins and user display-size settings change the reported width.
- Safe area insets are for planning. Read them at runtime with
env()rather than hard-coding the values here. - Social platform sizes are recommendations that change without notice. Check the verification date.
- The device catalogue is not exhaustive. It covers the models people actually search for, not every device ever shipped.
See also sources.