Why sticky add to cart matters
Long product pages bury the button: a shopper deep in reviews or specs decides to buy and has to scroll hunting for it. The sticky bar keeps the decision one tap away from anywhere on the page.
On mobile, where pages run longest, it matters most.
What the sticky bar should carry
- The add-to-cart button, unmistakably
- Price, and variant selection where it fits
- Compact product identity: thumbnail or name
- Restraint: thin enough not to eat the screen
Questions
When should the sticky bar appear?
Once the original button scrolls out of view, not on page load. Doubling the button above the fold clutters the exact screen that was already fine.
Does a sticky bar annoy shoppers?
Only when it’s tall, animated, or covers content. A slim, quiet bar reads as convenience; anything demanding attention reads as pressure.