Scroll depth on Shopify, section by section

Store Decode measures scroll depth on a Shopify homepage section by section, not as one percentage of the page. Each section gets a Views number: the share of the sessions that had it on the page in which at least half of it came into view. On Explore’s page map, a dashed line marks where the typical first screen ended on a phone or a computer.

The method in plain words

Scroll depth usually means how far down a page a visitor scrolled, as a share of the page’s height. The same percentage means different things on a phone and a computer, and on a long page and a short one. It also does not say which part of your page was seen.

So Store Decode asks a narrower question about each section of your theme: did it come into view in this visit? The script notes the moment at least half of a section is on the screen. A section too tall ever to show half of itself counts once it fills half the screen. Each section’s count of such visits, out of the visits that had it on the page, is its Views.

The script also notes which sections started on the first screen, before any scrolling. Over many visits that gives the line where the typical first screen ends.

What it means for your numbers

• Views usually falls as you go down the page. The drop between two sections tells you where visitors stop scrolling. A section near the bottom with low Views is not failing: few visits reach it.
• Each section has its own base. Views is a share of the sessions in which the section was on the page, scrolled to or not. A section added part-way through the window is not measured against visits that did not have it.
• Counts come first. Below 300 sessions of its own, a section shows a count, “N of M”, in place of a percentage, and carries no signal.
• Device matters. Every number states its device, its window and n. The device comes from the visitor’s window width, not from the browser’s name.
• One visit’s scroll depth is a rough fact. Activity can show how far one page view scrolled, as a percentage. It can show less than the visit scrolled. On a page with no tall section it is sampled about every 30 seconds while the tab is visible, so a short visit or a quick scroll can report less, or nothing. The merchant pages are built on each section’s Views instead.

When at least 35% of mobile homepage sessions, or 25% of desktop ones, never see anything below the second section, an observation can appear. It reads “N% of mobile visitors never see anything below the hero.” Its option is to shorten the hero so the next section shows sooner, then compare how many visitors see section 2 over the two weeks after. What a phone shows first answers that question on its own page.

In the sample store

Tidewell Home is an invented sample store, and every number here is made up. On mobile (Mobile · 7 days · n=4,100) the line sits after the Hero slideshow. The next section, Shop by category, was viewed by 3,731 of 4,100 sessions, so the line reads “9% didn’t view Shop by category”. Further down the page, Bestsellers was viewed by 1,642 of 4,100 sessions (40%) and the Footer by 451 of 4,100 (11%).

The exact rules

Views. A section counts as viewed in a session when at least 50% of it is visible. A section too tall to reach 50% counts when it fills at least half of the viewport. The base is the section’s own sessions: the sessions in which a page view listed the section. A percentage needs 300 of them on that device.

The first-screen line. On the Homepage tab of Explore, with Mobile or Desktop chosen, a dashed line labelled “Typical first screen ends” is drawn:

• Where. After the last section, in page order, that started on the first screen in at least half of its page views on that device.
• The bracket. An amber bracket beside the frame spans from the last section that started on the first screen in at least 75% of its page views to the last that did in at least 25%. It is a share of views, never a screen size.
• What it needs. At least 50 homepage page views on that device. Until then the map says “The first-screen line appears after 50 homepage views on this device.”
• The text beside it. “N% didn’t view” and the next section visible on that device, where N is 100 minus that section’s Views. While that section has fewer than 300 sessions of its own, the line prints a count: “N of M didn’t view”.
• Which device. There is no line on All devices. The phone frame is drawn at the most common window size among your visitors.

The line and the bracket are drawing decisions; the number beside the line is measured. Where a section starts is recorded when the script lists the sections, so images that load late can push sections lower than recorded. How Store Decode measures a Shopify store has the minimums for every other number.

See section by section how far visitors get on the sample store’s map