Analysis
Retention
Weekly cohorts and how many people come back
Retention groups users into weekly cohorts by the week of their first event and shows, for each following week, the share of the cohort that was active again.
Reading the table
Rows are cohorts (the week people first appeared), columns are weeks since then. Week 0 is always 100%; each later cell is the percentage of that cohort with at least one event in that week.
Parameters
- Periods: number of weeks to show, 1 to 12, default 8.
- Date range: which cohorts to include.
From the API
curl -X POST https://api.iforevents.com/v1/analytics/retention \
-H "X-Project-Key: <key>" -H "X-Project-Secret: <secret>" \
-H "Content-Type: application/json" \
-d '{"periods":8,"start":"2026-07-01T00:00:00Z","end":"2026-09-11T23:59:59Z"}'The key and secret pair is for scripts on your servers only; apps and browsers send the key alone (see Authentication).
The response lists cohorts with their size and the returning-user counts per period.
Tips
- Retention needs identified users: anonymous events do not form cohorts.
- Recent cohorts have fewer completed weeks; empty trailing cells mean "not yet", not zero.
- Compare cohorts before and after a release to see whether onboarding changes stuck.