Short answer
If you signed in to Proton on a shared or borrowed computer, you can end that session from your account settings rather than from the shared machine. Proton account settings include Security and privacy → Session management, with a list of active sessions.
Proton account settings include Security and privacy, Session management, with a list of active sessions. Source
From that list you have two options: revoke one device, or sign out everything except the session you are currently using.
Revoke beside a device signs that session out; Revoke all other sessions keeps the current session and signs out the others. Source
Before and after checklist
Use this as a short inventory-and-action routine. It is an editorial checklist, not a record of a test.
Before you revoke
| Step | What to do | Why it matters |
|---|---|---|
| 1 | Sign in to Proton on a device you control, ideally the one you are keeping. | You need a trusted session to manage the others. |
| 2 | Open Security and privacy → Session management. | This is where the active session list lives. |
| 3 | Read the list and note entries you do not recognise or no longer use. | The list shows devices or sessions, not proof of who used them. |
| 4 | Decide whether to revoke one entry or all others. | The two actions behave differently. |
After you revoke
| Step | What to do | Why it matters |
|---|---|---|
| 1 | Confirm the revoked entries are gone from the active list. | The list is your visible record of what remains signed in. |
| 2 | If you used Revoke all other sessions, check that your current session still works. | That action keeps the current session. |
| 3 | If you used Revoke on a single device, check whether any other forgotten entries remain. | One revocation does not clear the whole list. |
| 4 | Sign out of the shared computer itself if you still have access to it. | Revoking a session and signing out locally are separate habits; the reviewed claims cover the settings side. |
| 5 | Change your password if you have reason to think someone else had access. | Session revocation ends sessions; it is not a substitute for reviewing your credentials. |
What the session list can and cannot tell you
A session entry is a device or session associated with your account. It is not a statement about who was sitting at that device, and it does not by itself prove that anyone else used your account. Treat unfamiliar entries as a reason to review and revoke, not as proof of a person’s identity or intent.
The list is also not a complete history of everything that ever happened. It shows active sessions you can act on. If an entry is missing, that does not establish that no other access ever occurred.
The current-session exception
Revoke all other sessions is the convenient option when you are signed in on the device you want to keep: it signs out the others and keeps the current session. If you instead want to end only one device, use Revoke beside that entry. Choosing the wrong one is not destructive to your account, but it changes which sessions survive.
Failure boundaries: what revocation does not do
- It does not delete your Proton account. Ending sessions and closing an account are different actions. If your goal is account deletion, session revocation is not that step, and the reviewed claims here do not describe a deletion procedure.
- It does not erase files already downloaded or copied elsewhere. Revoking a session ends that session; it does not reach into a shared computer’s downloads folder, a synced copy, or a screenshot someone took.
- It does not prove who used a device. A session entry is not attribution evidence.
- It does not guarantee that every trace is gone. You can end sessions you can see and control; you cannot confirm from this list alone what happened on a machine you no longer have access to.
- It does not replace password hygiene. If you suspect compromise, session revocation is one step, not the whole response.
Where a username lookup fits, and where it does not
If part of your concern is that a username you use publicly is connected to accounts you did not expect, a public username search can surface matching profiles as leads. TraceSeek, the app covered by TruthsSeek, checks a username across 3,000+ platforms and offers a free first scan, with results typically returned in 20–30 seconds. Those are product statements, not independent measurements.
Two limits matter here. A username match is a lead, not proof of ownership or identity, and a username search is not a complete account inventory. TraceSeek cannot operate Proton settings, revoke sessions, or access private account data. For the task in this article — ending forgotten Proton sessions — the account settings are the relevant tool, not a lookup app.
If you are cleaning up accounts more broadly, keep a recovery method you control until any closure is complete, and do not treat removing a login connection or emptying a profile as proof that stored data was deleted.