At a glance
Funnel Conversion Drop (>5pp in 24h) is a Nerve Centre alert tracked from PostHog funnel data. It fires when your primary funnel’s end-to-end conversion rate falls by more than 5 percentage points inside a 24-hour window. A swing that large overnight is rarely organic; it usually points to a broken step, a deploy regression, or a tracking failure. This is one of the earliest revenue-at-risk signals PostHog can give you.
| What it counts | Alert events raised when primary funnel conversion drops more than 5 percentage points within 24 hours. |
| Sample type | Backend API data from PostHog funnel insights, evaluated against the alert rule on each refresh. |
| Why it matters | A sudden funnel drop is a leading indicator of lost orders. Catching it within 24 hours, rather than at month-end, is the difference between a quick fix and a quarter of leakage. |
| Reading the value | A non-zero count means the rule fired. Open the alert to see which step moved and when. |
| Currency | count |
| Time window | RT |
| Alert trigger | primary funnel conversion down >5pp in 24h |
| Sentiment key | ph_alert_conversion_drop |
| 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 Funnel Conversion Drop (>5pp in 24h) for a typical merchant on PostHog. Suppose your view-to-purchase funnel sat at 3.4% conversion all month, then dropped to 1.9% within a day of a checkout deploy on 14 Mar 26. That is a 1.5pp drop, which would not trip the rule, but a drop from 8.1% to 2.4% on a smaller funnel would. When the card shows an alert, open it, identify the step that lost volume, and cross-reference Biggest Funnel Step Drop-off to localise the break. 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 conversion rate this alert watches. |
ph_funnel_dropoff | Funnels sibling: which step is bleeding the most. |
ph_alert_event_volume_drop | Nerve Centre sibling: event volume collapse alert. |
ph_alert_tracking_broken | Nerve Centre sibling: core event stopped firing. |
ph_xc_funnel_vs_ecom_conversion | Cross-channel sibling: funnel vs platform conversion. |
Reconciling against the vendor’s own dashboard
Where to look in PostHog’s own dashboard: Open your primary funnel insight in PostHog and switch to the trend view to see conversion by day. The 24-hour drop the alert fired on should be visible as a step change. Confirm the funnel steps and conversion window match the profile configured in Vortex IQ. Why the Vortex IQ value may legitimately differ:| Reason | Direction | What to do |
|---|---|---|
| Conversion window. PostHog funnels allow a configurable conversion window; a mismatch shifts the rate. | Variable | Match the conversion window setting. |
| Funnel definition. The steps Vortex IQ watches may differ from the funnel you are viewing. | Variable | Confirm the same funnel is selected. |
| Low-volume noise. On small funnels, a few sessions swing the percentage hard. | Variable | Check the underlying step counts. |