Yes, signing into the same Google account with sync on carries history and open tabs between devices. That includes a work and a personal device, so a synced history entry can reach a second device long after the disguised session on the first one has ended. Docognito changes only what appears on the device you are using at the time.
What Chrome sync actually does
Chrome sync links a Google account to a browsing profile, and once switched on, it keeps categories of data, history, open tabs, bookmarks, saved passwords, consistent across every device signed into that same account. This is what lets someone start reading an article on a laptop and pick it up on a phone a few minutes later, since the phone's Chrome has already received the same tab from the sync service by the time they open it.
The feature works exactly as designed. It does not distinguish between a work device and a personal one; it only sees a Google account, signed in on however many devices that account is active on, and treats all of them as one synced set.
Where a work and a personal device end up connected
The most common way this happens is not deliberate. Someone signs into their personal Google account on a work laptop, perhaps to access personal bookmarks or a saved password, without switching sync off first, or signs into a work managed account on a personal phone for a similar reason. From that point, sync treats both devices as part of the same set, and history created on one becomes visible on the other, typically within moments.
your browser history being synced this way is a browser account feature, built by Google, operating independently of any website or extension running on either device. A page opened on a work laptop can appear in the history of a personal phone through this path with nothing else involved.
A single shared sign in can connect devices you assumed were separate
If the same Google account is signed into a work device and a personal device with sync on, treat their browsing history as one combined record, not two separate ones, regardless of which device you were actually holding at the time.
What crosses between synced devices, and what does not
| Category | Carries over with sync on | Notes |
|---|---|---|
| Browsing history | Yes | Entries appear on every synced device, not only the one that created them |
| Open tabs | Yes | Visible under the other devices list in Chrome's tab switcher |
| Saved passwords | Yes | Available for autofill on any synced device |
| Installed extensions | Often | Depends on whether extension sync is included in the account's sync settings |
| Local-only browser data, such as an extension's storage setting | No | Storage permission data is generally scoped per profile, not swept into account sync by default |
The first two rows are the ones with the most direct bearing on a work and personal device sharing a sign in, since they are exactly the kind of record a person assumes stays on the device they were using at the time.
How to keep the two separated on purpose
Separation is a setting, not a guess. Chrome supports multiple distinct profiles on one device, and using a separate profile for work sign ins against personal ones keeps their sync data apart entirely, since each profile syncs to whichever account it is signed into on its own. Within a single account, Chrome's sync settings also allow turning specific categories, history included, off individually, so tabs might sync while history does not, depending on what a person actually wants shared.
Where neither of those is set up, checking chrome://settings/syncSetup
shows exactly which categories are currently syncing for the signed in
account, which settles the question directly rather than by assumption.
Where a page disguise fits into this picture
Docognito redraws the visible page, redrawn as a document editor, the the browser tab title and the the tab icon for a person looking at the device you are actually using, while a tab stays open. Chrome sync operates independently of that, at the browser account level, moving history and open tabs between devices regardless of what any extension changed on the page in the moment. A synced history entry created while the disguise was on still carries the real page title and URL once sync writes it, since sync reads from Chrome's own history record, not from what an extension displayed. This is independent from keeping the assistant visibly usable while it looks like a document in the moment, which is the problem a page disguise actually solves.
What does Chrome sync actually move between your devices?
If a work and a personal device are signed into the same Google account with sync on, treat their history as shared, not separate, no matter which device a visit happened on. Use separate Chrome profiles, or turn off history sync for one account, to keep them apart on purpose. A page disguise changes what appears on the screen in front of you. It has no reach into what Chrome's own sync service moves between devices afterward.