Windows laptopsMonitors

15.6″ / 17″ Full HD @ 125% vs 24″ Full HD 1920×1080: screen size for websites

The 24″ Full HD 1920×1080 is 384px wider and 216px taller in CSS pixels. That’s enough for a layout that fits the 24″ Full HD 1920×1080 to spill on the 15.6″ / 17″ Full HD @ 125%.

15.6″ / 17″ Full HD @ 125%24″ Full HD 1920×1080
CSS viewport1536 × 8641920 × 1080
Visible on first load1536 × 729 (Chrome (Windows 11))1920 × 945 (Chrome (Windows 11))
Device pixel ratio1.251
Physical resolution1920 × 10801920 × 1080
Screen size15.6″24″
Aspect ratio16:916:9
Tailwind breakpoint2xl2xl
Bootstrap tierxxlxxl
Full-width image needs1920px1920px
Released––

See your site on both, side by side

Paste your address (or localhost:3000). doesitfit shows it on the 15.6″ / 17″ Full HD @ 125% and 24″ Full HD 1920×1080 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: 1536px vs 1920px

Headings and buttons wrap differently: a line that fits in 1920px can break onto two lines in 1536px. Anything with a fixed width between the two makes the narrower screen scroll sideways (fix it).

Height: 864px vs 1080px

On first load a page shows 729px on the 15.6″ / 17″ Full HD @ 125% and 945px on the 24″ Full HD 1920×1080, so “above the fold” differs by 216px.

Questions people ask

Is the 15.6″ / 17″ Full HD @ 125% screen bigger than the 24″ Full HD 1920×1080 for websites?

The 24″ Full HD 1920×1080 is 384px wider and 216px taller in CSS pixels. That’s enough for a layout that fits the 24″ Full HD 1920×1080 to spill on the 15.6″ / 17″ Full HD @ 125%.

What are the viewport sizes of the 15.6″ / 17″ Full HD @ 125% and 24″ Full HD 1920×1080?

15.6″ / 17″ Full HD @ 125%: 1536 × 864 CSS px (DPR 1.25). 24″ Full HD 1920×1080: 1920 × 1080 CSS px (DPR 1).

Do I need to test my site on both?

Yes if your layout has anything close to 1920px wide. Test the narrower one first: it’s where things spill.

More comparisons