Windows laptops

HD laptop 1366×768 vs 15.6″ / 17″ Full HD @ 125%: screen size for websites

The 15.6″ / 17″ Full HD @ 125% is 170px wider and 96px taller in CSS pixels. That’s enough for a layout that fits the 15.6″ / 17″ Full HD @ 125% to spill on the HD laptop 1366×768.

HD laptop 1366×76815.6″ / 17″ Full HD @ 125%
CSS viewport1366 × 7681536 × 864
Visible on first load1366 × 633 (Chrome (Windows 11))1536 × 729 (Chrome (Windows 11))
Device pixel ratio11.25
Physical resolution1366 × 7681920 × 1080
Screen size15.6″15.6″
Aspect ratio16:916:9
Tailwind breakpointxl2xl
Bootstrap tierxlxxl
Full-width image needs1366px1920px
Released––

See your site on both, side by side

Paste your address (or localhost:3000). doesitfit shows it on the HD laptop 1366×768 and 15.6″ / 17″ Full HD @ 125% at their exact sizes, next to each other.

Free, no sign-up. Or ask Claude, ChatGPT or Codex to check it.

What the difference means for your site

Width: 1366px vs 1536px

Headings and buttons wrap differently: a line that fits in 1536px can break onto two lines in 1366px. Anything with a fixed width between the two makes the narrower screen scroll sideways (fix it).

Height: 768px vs 864px

On first load a page shows 633px on the HD laptop 1366×768 and 729px on the 15.6″ / 17″ Full HD @ 125%, so “above the fold” differs by 96px.

Questions people ask

Is the HD laptop 1366×768 screen bigger than the 15.6″ / 17″ Full HD @ 125% for websites?

The 15.6″ / 17″ Full HD @ 125% is 170px wider and 96px taller in CSS pixels. That’s enough for a layout that fits the 15.6″ / 17″ Full HD @ 125% to spill on the HD laptop 1366×768.

What are the viewport sizes of the HD laptop 1366×768 and 15.6″ / 17″ Full HD @ 125%?

HD laptop 1366×768: 1366 × 768 CSS px (DPR 1). 15.6″ / 17″ Full HD @ 125%: 1536 × 864 CSS px (DPR 1.25).

Do I need to test my site on both?

Yes if your layout has anything close to 1536px wide. Test the narrower one first: it’s where things spill.

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