Why did my session count drop in Amplitude?
The Amplitude help pages give 4 common reasons. The first to rule out: Events marked as outside any session are left out of every session number, so they can arrive without adding sessions.
What causes it?
Events marked as outside any session are left out of every session number, so they can arrive without adding sessions.
In the Amplitude help:
A session ID of -1 excludes the event from all session metrics.
Track sessions | Amplitude Docs, read 2026-11-12.Events sent from a server through Amplitude's HTTP API are outside sessions by default, so moving tracking to a server can lower session counts.
In the Amplitude help:
For events sent through the HTTP API, Amplitude defaults to a session ID of -1.
Track sessions | Amplitude Docs, read 2026-11-12.How long a quiet gap can last inside one session is a setting, so a longer timeout can join visits that used to count as separate sessions.
In the Amplitude help:
Amplitude counts events from the same user that occur within the specified timeout interval as part of one session.
Track sessions | Amplitude Docs, read 2026-11-12.Only active events make up a session, as Amplitude's docs say, so events that are not active do not add sessions.
In the Amplitude help:
Sessions only include active events.
Track sessions | Amplitude Docs, read 2026-11-12.
How do I check it myself?
Check the chart's date range, since a session counts on the day it started, not the day it ended.
In the Amplitude help:
The start time must fall within a chart's selected date range for Amplitude to include the session on that chart.
Track sessions | Amplitude Docs, read 2026-11-12.Check whether anyone set conditions for what counts as a session, since a session has to meet every one of them.
In the Amplitude help:
A session must meet all configured conditions to count.
Track sessions | Amplitude Docs, read 2026-11-12.
How does Amplitude work with Feder?
- Connect Amplitude to Feder and it joins your Visits apps.
- When you connect Amplitude, Feder checks the connection straight away and shows Connected only when that check passes. If a reading cannot be taken later, Feder shows it as not read, never as zero.
Some numbers are too quiet to judge daily, such as a form filled in a few times a week. Until there is enough of your own history to judge a change, Feder says it is still learning and scores nothing, rather than guessing.
See whether you can trust the numbers in Amplitude, one of your Visits apps. Feder only reads. It never changes anything in Amplitude.
What else goes wrong with these numbers?
- Why did my user count drop in Amplitude?Amplitude
- Why did my user count jump in Amplitude?Amplitude
- Why did Google Analytics stop collecting data?Google Analytics
- Why aren't my key events showing in Google Analytics?Google Analytics
- Why does Google Analytics show (not set)?Google Analytics
See every question.
Where do these answers come from?
Every cause and check on this page comes from the Amplitude help pages, quoted above with the date we read them. Last reviewed 2026-11-12. We read them again by 2027-11-12. If one changes, this page changes or comes down.