Avg Scroll Depth %, FullStory

Avg Scroll Depth % for FullStory stores. Tracked live in Vortex IQ Nerve Centre. How to read it, why it matters, and how to act on it.

Metrics type: Supporting Metrics • Category: Page Analysis

At a glance

Avg Scroll Depth % measures how far down the page visitors typically scroll, expressed as a percentage of the page height. FullStory captures scroll behaviour from the session timeline. It tells you whether your content below the fold is actually being seen. A low average means visitors stop near the top, so anything important, product details, reviews, calls to action, sat below the line is invisible to most of them. It is a layout and content-priority signal, not a frustration one.

What it counts	The average maximum scroll depth reached per session, as a percentage of page height, captured by FullStory across the period.
Sample type	Backend API data from FullStory, refreshed on the standard data refresh.
Why it matters	It shows whether below-the-fold content is seen. Key information stranded past the average scroll depth is effectively invisible, which wastes the content and any conversion element living there.
Reading the value	Compare the current period to the prior period and read by template. A low value on a long page suggests moving important elements higher.
Currency	percent
Time window	30D vsP
Alert trigger	-
Sentiment key	fs_scroll_depth_avg
Roles	owner, marketing

Calculation

Calculated automatically from your FullStory data. Vortex IQ reads the maximum scroll position reached in each session, normalises it against page height, and averages it across sessions for the period. See the At a glance summary above for what the metric tracks and the worked example below for a typical reading.

Worked example

A representative reading of Avg Scroll Depth % for a typical merchant on FullStory. Suppose a long product page averages 38% scroll depth. The size guide and reviews, the two things shoppers ask for most, sit at 70% and 85%, so most visitors never reach them. Moving reviews up near the add-to-cart area lifts both scroll engagement and conversion. Without this card the buried content would have looked underused for no obvious reason. For deeper investigation, use Vortex Mind to compare scroll depth by template; for natural-language exploration, ask Ask Viq which pages people stop scrolling on.

Sibling cards merchants should reference together

Card	Why merchants reach for it
fs_pages_per_session	A companion depth-of-engagement signal across pages.
fs_worst_frustration_pages	Where shallow scrolling overlaps with frustration.
fs_page_load_to_first_interaction	Slow pages can suppress scrolling.
ful_avg_session_duration	A broader engagement companion.

Reconciling against the vendor’s own dashboard

Where to look in FullStory’s own dashboard:

FullStory exposes scroll behaviour through its heatmaps and page-level reporting. Confirm period boundaries and page scope match the Vortex IQ profile to reconcile cleanly.

Why the Vortex IQ value may legitimately differ:

Reason	Direction	What to do
Page-height basis. Depth is relative to page height, which changes if a template was edited mid-period.	Variable	Check for layout changes in the window.
Period boundary. Vortex IQ uses 30-day rolling by default; FullStory dashboards may use calendar periods.	Variable	Match the period range.
Device mix. Mobile and desktop scroll very differently, so a shift in mix moves the average.	Variable	Check the device split.

Cross-connector reconciliation: complement with the page-engagement and frustration cards. For divergence investigations, use Vortex Mind.

Known limitations / merchant FAQs

Q: How often does Avg Scroll Depth % update? The card refreshes on the standard data refresh (typically every 30-60 minutes for live integrations). For real-time signals, force a manual refresh from the dashboard.

Q: Is a low scroll depth always bad? No. On a short page or one designed to convert above the fold, a low average is fine. The signal matters most on long pages where key content lives lower down.

Q: Why does my FullStory dashboard show a different number? The most common reasons are the page-height basis, period boundaries, and device mix. Match these before assuming a real divergence.

Q: Can I customise the alert threshold? Alert thresholds are configurable per profile in the Alert Rules tab. Set a threshold that reflects the layout goals of your key templates.

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Tracked live in Vortex IQ Nerve Centre

Avg Scroll Depth % is one of hundreds of KPI pulses Vortex IQ tracks across FullStory and 70+ other ecommerce connectors. Nerve Centre runs the detection layer; Vortex Mind investigates the cause when something moves; Ask Viq lets you interrogate any number in plain English.

Start for free or book a demo to see this metric running on your own data.