How to see where your Google Account is signed in and sign out of unknown devices

Steps

1. Open your Google Account pageOn Android, open the Settings app, tap Google, then your name and “Manage your Google Account”. On iPhone, open the Gmail app and tap your profile picture at the top right, then “Manage your Google Account”. On a computer, type myaccount.google.com into your browser.💡 Shortcut: typing google.com/devices into your browser takes you straight to the device list.
2. Go to the device listTap “Security & sign-in”; on a computer this section is in the menu on the left. Find the “Your devices” panel and select “Manage all devices”. Google may ask for your password again to confirm it's you.
3. Read the whole listThe list shows phones, computers and other devices where your account is signed in right now or was signed in during the last few weeks. Tap a device or a session for details. Devices and sessions you've signed out of are marked “Signed out”.
4. Read times and locations correctlyThe time shown is the last time the device communicated with Google's systems. Because apps like Gmail or Calendar sync in the background, this time can be more recent than when you last used the device. The location may also be a nearby place rather than the exact spot, and somewhere you stopped briefly, such as an airport, can appear too.
5. Pick out your own devicesSome entries may look unfamiliar at first but still be yours. A new device you started using, someone else's phone or a public computer you signed in on, or a device you reset to factory settings can all appear in the list. Signing in on a new browser or in a private window, re-entering your password, or giving an app access to your account also creates a separate session on the same device.
6. Sign out of devices you don't needIf you see a device that's lost, sold, no longer yours or never belonged to you, tap it and select “Sign out”. Several sessions with the same device name could come from one device or from several. If you're not sure, sign out of every session listed under that name.
7. Report a device you don't recogniseIf a device you truly don't recognise is still in the list, tap “Don't recognize a device?” on the devices page. Then follow the security steps on the screen in order. Seeing a different browser from the one you normally use (for example Safari when you always use Chrome) is also a warning sign.
8. Review recent security eventsGo back to “Security & sign-in” and, on the “Recent security events” panel, select “Review security events”. If there's anything you didn't do, select “No, it wasn't me” and follow the steps on the screen. If it was you, select “Yes”.
9. Change your passwordIf you saw a suspicious device or event, change your password straight away. On Android and on a computer, under “Security & sign-in”, tap “Password” under “How you sign in to Google”; on the page opened from Gmail on iPhone, use “Password” in the “Personal info” section. Enter and confirm the new password. Once it changes, you're signed out everywhere except devices you use to verify it's you when signing in, and some devices with third-party apps or home devices you've given account access to.
10. Protect your account for goodIf you haven't already, turn on 2-Step Verification; even if your password leaks, signing in will also need your phone or a security key. In Gmail settings, remove any labels, filters or forwarding rules you didn't set up. In Chrome, remove extensions you don't recognise and update the browser.