Biggest Funnel Step Drop-off, PostHog

Biggest Funnel Step Drop-off for PostHog stores. Tracked live in Vortex IQ Nerve Centre. How to read it, why it matters, and how to act on it.

Metrics type: Key Metrics • Category: Analytics

At a glance

Biggest Funnel Step Drop-off is a funnels metric tracked from PostHog data. It pinpoints the single step in your primary funnel where the most users abandon, expressed as the drop-off percentage between two consecutive steps. Where Primary Funnel Conversion tells you the funnel is leaking, this card tells you exactly where. It turns a vague “conversion is down” into a specific “the cart-to-checkout step is losing 62% of users”.

What it counts	The funnel step with the largest drop-off, and the percentage of users lost at that step.
Sample type	Backend API data from PostHog funnel insights, refreshed on the standard data refresh.
Why it matters	The biggest leak is usually the highest-leverage fix. Naming the worst step turns funnel analysis into a clear next action.
Reading the value	The card names the step and its drop percentage. A step losing more than 40% is flagged as a priority.
Currency	percent
Time window	30D
Alert trigger	any step >40% drop
Sentiment key	ph_funnel_dropoff
Roles	owner, marketing

Calculation

Calculated automatically from your PostHog data. 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 Biggest Funnel Step Drop-off for a typical merchant on PostHog. Suppose your funnel converts 100% to product view, 46% to add to cart, then only 14% to purchase. The largest single drop is add to cart to purchase, losing about 70% of carts. The card names that step. After a guest-checkout change on 27 Mar 26, if the worst step shifts to product view to add to cart, you know the friction moved earlier. Cross-reference Primary Funnel Conversion for the overall rate and Avg Time to Convert for hesitation signals. For deeper investigation, use Vortex Mind to trace upstream causes; for natural-language exploration, ask Ask Viq.

Sibling cards merchants should reference together

Card	Why merchants reach for it
ph_funnel_conversion	Funnels sibling: the overall conversion rate.
ph_funnel_time_to_convert	Funnels sibling: how long the journey takes.
ph_paths_top_route	Funnels sibling: the most common route through the store.
ph_replays_with_rage_clicks	Session Replay sibling: frustration at the drop step.
ph_alert_conversion_drop	Nerve Centre sibling: rapid conversion drop alert.

Reconciling against the vendor’s own dashboard

Where to look in PostHog’s own dashboard:

Open your primary funnel insight in PostHog. The per-step bars show the conversion and drop at each stage, and PostHog highlights the largest fall. The step with the steepest decline should match the one this card names.

Why the Vortex IQ value may legitimately differ:

Reason	Direction	What to do
Funnel definition. Adding or removing a step changes where the biggest drop appears.	Variable	Confirm the same step set.
Conversion window. A short window pushes drop-off later in the funnel.	Variable	Match the conversion window.
Filter scope. Device or channel filters can move the worst step.	Variable	Align the filters.

Cross-connector reconciliation: complement with sibling cards in the same category for the full diagnostic picture. For divergence investigations, use Vortex Mind.

Known limitations / merchant FAQs

Q: How often does Biggest Funnel Step Drop-off 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 high drop-off always bad? Not always. The drop from pageview to product view is naturally large because many visitors browse the homepage and leave. Focus on drops that are large relative to a normal benchmark for that step.

Q: The biggest drop moved to a different step. Why? A fix to the previous worst step, or a new friction point introduced by a deploy, can shift where most users abandon. Treat a moving worst step as a signal that the funnel shape changed.

Q: Can I customise the alert threshold? Yes, alert thresholds are configurable per profile in the Alert Rules tab. Adjust to match your business baseline rather than relying on the generic default.

---

Tracked live in Vortex IQ Nerve Centre

Biggest Funnel Step Drop-off is one of hundreds of KPI pulses Vortex IQ tracks across PostHog 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.