Designing for slow connections, not your MacBook
Most of your visitors aren't on gigabit fiber with an M3 Pro. Design with their reality in mind — your conversion rate will thank you.
If you only test your designs on the machine you designed them on, you’re going to have a bad time. The median user visiting your site is on a mid-range Android phone, on an LTE connection that briefly drops to 3G whenever they walk into a building.
The checklist we use
When we hand off a design spec, it includes a short “low-bandwidth” section:
- Initial paint under 1.5s on 3G — this dictates what can be above the fold.
- Images never larger than they need to render at. Serve
srcset, always. - Text stays readable without web fonts — add a proper fallback stack.
- Tap targets at least 44×44px. Thumbs aren’t mice.
- Forms work without JS. Then enhance.
A practical trick
We throttle our own browsers to “Fast 3G” once per sprint. If the design still feels fine, we ship. If it doesn’t, we iterate. It’s a 5-minute habit that’s caught more problems than any automated audit.
The business case
Clients used to push back on performance constraints. They stopped once we started attaching the numbers: for one B2B client, moving from LCP 4.1s to 1.8s correlated with a 22% lift in demo requests. Your visitors’ patience is a rounding error on your funnel. Treat it that way.
- #ux
- #performance
- #accessibility