Retention: do users come back?

• Of the people who signed up, what share came back to create a report on day 7?
• After you changed onboarding, did the later cohorts return on day 7 more often than the earlier cohorts?
• Does the day 1 return rate stay the same as more people arrive, or does it fall?

Retention cannot answer "how many people who signed up created a report at any time later?" It counts a return only on the exact day. For that question, use Funnels.

• Returns after your end date. Sequential looks for returns up to your end date plus your largest day. So a cohort near the end of the date range can still show a day 30, if that day has already happened.
• Overall figures. Each tile adds the returned people of the cohorts that reached that day. It then divides that sum by the total size of those cohorts. So larger cohorts have more weight.
• Exact day only. Day N is not "on or after". A person who returns on days 5 and 9 does not count on day 7.
• Existing users. With new people only, a person who did the start event before the date range is in no cohort, so Retention shows how new people come back. With everyone active in the range, that person joins the cohort of their first start event in the range, as if they were new.
• The start-date cohort. With new people only, the cohort of your start date holds only the people who are new on that day, as every other cohort does. With everyone active in the range, it holds every existing user who did the start event on that day. Read it with care.
• Weekly rows. Each person has one cohort day. So a week row is the sum of the daily cohorts of that week, with no person counted twice.
• Before-and-after comparisons. To compare cohorts before and after a change, start the date range well before the change. A cohort holds the people whose first start event is on its day. A person can be new to Sequential but not new to your product, for example after you install the SDK. So treat the comparison as a trend only.

Suppose that the row for 1 September has People 120. Its Day 7 cell shows 18.3% with 22 under it. So 22 of the 120 people whose first start event ever was on 1 September had a return event on 8 September.

While the analysis runs, the Analyse retention button shows Analysing…. When it is done, a short "Retention analysed" message shows.

The date bar. You do not need its Apply button. It shows only after you change a date. Until then, the bar shows Applied.

Apply only clears the previous results. Analyse retention always uses the dates that are in the boxes now.

The days. Each day is a chip after on day. The page refuses a day that it cannot use, and says why. The list does not change then:

• "Enter a whole number of days from 1 to 365."
• "Day N is already in the list."
• "You can measure at most 10 days. Remove a day first."

With no day in the list, Analyse retention is off, and the page says "Add at least one day to analyse". After a refused day, until you type in + day again, it says "Fix the day value to analyse".

The results header. The header of Answer repeats the period and the days.

If your browser is not set to UTC, the period in the header can be one day off. East of UTC, the start shows one day early. West of UTC, the end shows one day late. The analysis itself uses the dates in the boxes.

No cohorts. If no one did the start event in the date range, the page says why, instead of a table of zeros.

Switching project. The results clear when you switch to a different project.

From 11 October 2026, you can save a retention question for the project.

1. Set the start event, the return event, the days and Group by. Optionally, set Only people who….
2. Click Save as view.
3. Enter a name in Retention view name and click Save retention view.

• The view keeps the question, its days, its grouping and Count. A view that you saved before Count existed opens with new people only. It does not keep the dates: it uses the dates in the bar.
• Through the API, a saved retention view keeps Count as cohort: first_time (new people only) or first_in_range (everyone active in the range). A view without cohort reads as first_time. From 13 October 2026, Sequential refuses any other value with 422 invalid_definition at /cohort. The page offers only the two values.
• The view shows as a pill under Saved retention views:, on Dashboard under Saved items, and in the search (⌘K) by its name, marked Retention, when you type.
• A pill or a card puts the question on the page. Then click Analyse retention.
• Owners, admins and members can save. Viewers can only apply.

See Filters, date ranges and saved views.

Call identify:

• when a person signs up or signs in
• on each page load, for a person who is already signed in

Always use the same value for one person. Sequential counts two different values as two people.

Retention counts users by the user id on each event. After your app calls identify, that id is the value you passed. Before that, it is an anonymous id that the SDK keeps in that browser or app.

• A person who uses a laptop and a phone counts as two users in two cohorts. A return on the second device is not a return for the first.
• A private window or cleared browser storage starts a new anonymous id. The same person then joins a new cohort as a new user.
• If the browser blocks all storage, the Sequential SDK starts a new id on every page load.

With the Sequential SDK, PostHog or Mixpanel, the visit where a person is identified is not split. Retention uses the link from identify to the anonymous id. So the events from before identify count for the identified person.

With Amplitude, Pendo or Smartlook, nothing links the two ids. Each time a person starts anonymous and is then identified, an extra anonymous user joins the cohort of that day. That user usually does not return. This happens:

• on a sign-up
• on a sign-in on a new device or in a private window
• on a sign-in after a sign-out reset

This makes cohorts bigger and makes their rates lower.

Shared devices need a sign-out reset. When a person signs out, call your SDK's reset. In the Sequential SDK, this is sequential.reset(). The next person on that device then gets a new anonymous id. Without the reset, Sequential counts that person as the previous user returning.

Sequential's Smartlook-compatible script stores only the identify call under your user id. Every other event stays under the Smartlook visitor id. So each identified person counts as two users:

• the visitor, with all their activity
• your user id, which is active only on the days when identify runs

See Moving from Smartlook.

An agent with analytics:read reads retention with the tool retention_analysis. It takes cohort:

• first_time, the default: the page's new people only. Each person joins the cohort of their first start event ever, when it is in the window.
• first_in_range: the page's everyone active in the range, the rule before 12 October 2026. Each person joins the cohort of their first start event in the window, so a person who was active before the window joins a cohort as if they were new.

The answer gives cohort and cohorts_complete:

• true: Sequential still holds all the events of the project, so the new people are new.
• false: retention can have deleted older events of the project. A person whose first visit was deleted can look new. Sequential checks the period that each stored day of events was kept with, so a shorter or longer period of the organisation does not change the answer for events already stored.
• null: Sequential could not check it.

With first_in_range, cohorts_complete is always true. POST /api/retention takes the same cohort.