Screen pixel density (PPI) from resolution and diagonal, physical size, CSS view...

{ "method": "GET", "queryParams": { "cssWidth": 400, "diagonalIn": 27, "dpr": 1, "heightPx": 1440, "widthPx": 2560 }, "type": "http" }

{ "example": { "asOf": "2026-10-11T14:32:44.713Z", "cssPixelPhysicalMm": 0.233487, "cssViewportHeight": 1440, "cssViewportWidth": 2560, "degraded": false, "disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.", "dotPitchMm": 0.23349, "dpr": 1, "heightInches": 13.2371, "heightMm": 336.221, "idealDprForReferencePixel": 1.1332, "imageWidthsForCssWidth": { "1.5x": 600, "1x": 400, "2x": 800, "3x": 1200, "atThisDpr": 400, "cssWidth": 400 }, "megapixels": 3.6864, "notChecked": [ "the real device pixel ratio (browsers and OS scaling set it, not the panel)", "non-square pixels and pentile subpixel layouts", "…2 more" ], "ppi": 108.7855, "ppiClass": "STANDARD", "reasons": [ "One CSS pixel spans 0.00919 in (0.2335 mm) on this screen at DPR 1; the CSS reference pixel is 1/96 in.", "Bands: under 120 PPI standard, 120 to 220 high, above 220 very high." ], "source": "PPI = sqrt(w^2 + h^2) / diagonal; CSS reference pixel = 1/96 in; computed locally", "summary": "2560 x 1440 on a 27 inch screen is 108.79 PPI (23.53 x 13.24 in); 2560 x 1440 CSS px at DPR 1.", "verdict": "STANDARD", "widthInches": 23.5325, "widthMm": 597.727 }, "type": "json" }