Session Replays Captured, PostHog

Session Replays Captured 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

Session Replays Captured is a session-replay metric tracked from PostHog data. It counts how many session recordings PostHog captured in the period. This is a PostHog-distinctive health check: the replay count should track your session count closely, so a widening gap between the two means capture is failing, sampling is too aggressive, or recordings are being dropped. Watch it to keep your qualitative data as trustworthy as your quantitative.

What it counts	The number of session replays captured by PostHog in the period, compared against the prior period.
Sample type	Backend API data from PostHog session-replay recordings, refreshed on the standard data refresh.
Why it matters	Replay count should move with session count. A divergence is an early sign that recording broke or sampling silently changed, leaving you blind on the qualitative side.
Reading the value	Compare today, 7-day, and 30-day reads against the prior period, and against your session count. They should rise and fall together.
Currency	count
Time window	T/7D/30D vsP
Alert trigger	-
Sentiment key	ph_session_replay_count
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 Session Replays Captured for a typical merchant on PostHog. Suppose you log about 40,000 sessions a week and capture roughly 38,000 replays, a healthy near-parity. After a config change on 16 Jun 26, replays fall to 22,000 while sessions hold at 40,000. The replay count diverged from sessions, so recording is dropping more than half of all visits. Cross-reference Session Replay Coverage % to quantify the gap and Sessions for the denominator. 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_session_replay_coverage	Session Replay sibling: replays as a share of sessions.
ph_replay_avg_duration	Session Replay sibling: average replay length.
ph_replays_with_rage_clicks	Session Replay sibling: frustrated sessions.
pos_sessions	Audience sibling: total sessions, the denominator.
ph_health_score	Executive sibling: overall tracking health.

Reconciling against the vendor’s own dashboard

Where to look in PostHog’s own dashboard:

In PostHog, open Session Replay and read the count of recordings for the period. The total there should align with this card. Then compare it to your session count in a sessions insight: a large gap points to sampling or capture issues rather than a counting difference.

Why the Vortex IQ value may legitimately differ:

Reason	Direction	What to do
Replay sampling. A sampling rate below 100% intentionally captures only a fraction of sessions.	Variable	Confirm the sampling rate.
Minimum duration. Very short sessions may not produce a recording.	Variable	Account for the minimum-duration rule.
Retention window. Older recordings may have aged out of storage.	Variable	Check the replay retention period.

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 Session Replays Captured 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: Why is my replay count lower than my session count? Some gap is normal: replay sampling, minimum-duration rules, and unsupported browsers all reduce capture. A small, stable gap is fine; a sudden widening is the signal to investigate.

Q: Recordings dropped sharply. What broke? Common causes are a sampling rate lowered by mistake, a billing or quota limit reached, or the replay snippet failing to initialise after a deploy. Check the replay configuration first.

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.

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Tracked live in Vortex IQ Nerve Centre

Session Replays Captured 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.