Feature request: Add sequential session numbers to session replays for easier reference and communication

Start by tracing the session_replay area from the replay list and detail pages described in the request, then inspect how replay ordering and retention are represented. Done means session numbers are stable per person, remain unchanged as sessions are added or pruned, and appear in the relevant UI views.

Feature request

Is your feature request related to a problem?

It would be valuable to have each session replay in PostHog assigned a simple, sequential number—such as 1, 2, 3, etc.—for each person/user. This number would appear alongside the session in the UI and remain consistent for that user, regardless of the total number of sessions. Session numbers should be ordered chronologically, starting from the earliest accessible session for each user.

Problem this solves:

• Makes it easier to reference specific sessions in triage notes, bug reports, and team communication.
• Improves clarity when communicating about user behavior or issues across multiple sessions (e.g., “sessions 5, 12, and 23”).
• Reduces the need to repeatedly copy/paste full URLs or long replay IDs
• Provides a quick way to gauge a user’s activity level and session history at a glance.

Describe the solution you'd like

• Assign a sequential session number to each session for a given user/person, visible in the session replay list and detail pages.
• The numbering shouldn't update as new sessions are recorded and as older sessions are pruned due to retention limits.
• The session number should be unique only within the context of a single user/person (i.e., every user has their own session 1, 2, 3, etc.).
• Optionally, allow searching or filtering sessions by session number in addition to current filters.

Describe alternatives you've considered

Use the current replay IDs or, share private / public links to the replays

Additional context

From: https://posthoghelp.zendesk.com/agent/tickets/33807 (moved to PostHog: https://us.posthog.com/project/2/support/tickets/35641)

Debug info

Kind: feedback

Target area: session_replay

Report event: http://go/ticketByUUID/4cda02ee-fbf4-4e71-a51c-8565548a17b4

Session: https://us.posthog.com/project/sTMFPsFhdP1Ssg/replay/0197e5ed-8c4a-730b-9725-522b15bdcf86?t=547

Exceptions: https://us.posthog.com/project/2/error_tracking?filterGroup=%7B%22type%22%3A%22AND%22%2C%22values%22%3A%5B%7B%22type%22%3A%22AND%22%2C%22values%22%3A%5B%7B%22key%22%3A%22%24session_id%22%2C%22value%22%3A%5B%220197e5ed-8c4a-730b-9725-522b15bdcf86%22%5D%2C%22operator%22%3A%22exact%22%2C%22type%22%3A%22event%22%7D%5D%7D%5D%7D

Location: https://us.posthog.com/project/96779/replay/home?sessionRecordingId=0197e5c0-1a4b-7876-be5b-ffa51f19956c

Persons-on-events mode for project: person_id_override_properties_on_events