At a glance
Daily Active Users is the count of unique users who triggered at least one tracked event in Amplitude on a given day. In product analytics it is the foundational pulse of audience size: how many distinct people are actually using your store each day, derived from Amplitude’s unique-user counting rather than raw pageviews. It is the denominator behind stickiness, retention, and engagement reads, so most other Amplitude cards make sense only once you can see whether your active base is growing, flat, or shrinking.
| What it counts | Unique users who fired one or more tracked events in Amplitude during the day, deduplicated by Amplitude’s user identity (Amplitude ID or user ID). |
| Sample type | Backend API data from Amplitude, refreshed on the standard data refresh. |
| Why it matters | DAU is the headline measure of live audience size and the base for stickiness and retention. A sustained drop usually signals either lost demand or a tracking break, both of which need fast triage. |
| Reading the value | Compare today, 7-day, and 30-day windows against the prior period. Steady or rising DAU is healthy; a sharp single-day fall often points to instrumentation rather than real audience loss. |
| Currency | count |
| Time window | T/7D/30D vsP |
| Alert trigger | drop >15% vsP |
| Sentiment key | amp_dau |
| Roles | owner, marketing |
Calculation
Daily Active Users is the count of distinct users who logged at least one event in Amplitude during the selected day, deduplicated on Amplitude’s user identity so a person browsing across multiple sessions or tabs counts once. Vortex IQ reads this directly from the Amplitude integration for the current window and compares it against the equivalent prior 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 Daily Active Users for a typical merchant on Amplitude. Suppose the card shows 8,200 DAU for today against a prior-period baseline of roughly 8,000, a gentle climb that tracks a small uplift in paid traffic. The 7-day window sits near 7,900 and the 30-day window near 7,600, so the recent days are pulling the average up. Now imagine the next morning the card reads 4,100, a fall of around 50% versus the prior day, well past the alert trigger. That magnitude rarely reflects half your audience vanishing overnight; it usually means a core event stopped firing or the SDK failed to load on a key template. Vortex Mind traces the drop upstream to check whether event volume and core events fell in lockstep (a tracking break) or whether sessions and traffic sources also dipped (a genuine demand drop). Ask Viq lets you ask, in plain English, “why did DAU fall yesterday and which events stopped firing” without building a chart by hand.Sibling cards merchants should reference together
| Card | Why merchants reach for it |
|---|---|
amp_wau | Weekly Active Users smooths daily noise and is the other half of the stickiness ratio. |
amp_event_volume | Total Event Volume rises and falls with DAU; a divergence flags a tracking issue. |
amp_stickiness_dau_mau | Stickiness (DAU/MAU) shows how habitually your active base returns. |
amp_health_score | Tracking Health Score confirms whether a DAU drop is real or instrumentation. |
amp_users | Users gives the broader audience total behind the daily-active slice. |
Reconciling against Amplitude
Where to look in Amplitude’s own dashboard: Open a User Activity or Active Users chart in Amplitude, set the measure to Daily Active Users, and use Event Segmentation with the “uniques” measure on your tracked events to cross-check. The Dashboards section often carries a saved DAU chart; confirm its date range and any saved segments before comparing. Amplitude’s active-user counts are unique-user based, so match its identity resolution settings to the Vortex IQ profile. Why the Vortex IQ value may legitimately differ:| Reason | Direction | What to do |
|---|---|---|
| Period boundary. Vortex IQ compares today, 7-day, and 30-day rolling windows; Amplitude charts may use calendar days or custom ranges. | Variable | Match the date range and window granularity. |
| Time zone. Amplitude buckets activity by the project time zone; Vortex IQ aligns to the merchant reporting time zone. | Marginal | Confirm both use the same time zone. |
| Filter or segment scope. Profile-level filters (platform, test users, internal traffic) may narrow the Vortex IQ view versus an all-events Amplitude chart. | Variable | Align the segment and event filters. |