61% of our users have never seen our product on a fast connection.

We logged connection speed metadata across 2.1 million sessions over 60 days.

Under 5 Mbps: 24%
5–20 Mbps: 37%
20–100 Mbps: 28%
Over 100 Mbps: 11%

61% of sessions were under 20 Mbps. Our median asset payload per page was 4.2 MB. On a fast connection that was invisible. On a 5 Mbps connection it was 7 seconds of loading. Our office had gigabit fiber. Our users had hotel wifi, mobile hotspots, and shared connections in buildings with too many people and not enough bandwidth.

We built a low-bandwidth mode that loaded a text-first version with images on demand. Median payload dropped to 480 KB. Session length in the under-5-Mbps group rose 34%, and bounce rate in that group dropped from 51% to 28%.

What connection speed are you designing for, and what connection speed do your users actually have?