First: sync is a membership feature
Multi-device sync is part of membership. Without it, nothing syncs automatically and each device works on its own — that is not a fault.
You can still move data across once with export / import; export is unlimited.
Note that using your own WebDAV server also requires membership. Membership covers the ability to sync across devices; you choose where the data lives, and your own server has no size limit.
Check in this order
1. Are both devices on the same account?
The most common cause. Compare the account email on the My page of each device.
2. Trigger a sync manually
The sync card at the top of the home screen has "Sync now". Watch what it reports — a specific error is far easier to act on than silence.
3. Network
Sync needs a connection. On a corporate network or behind a proxy, check that it is not being blocked.
4. Has the other device synced?
Sync is not a live push. Device A uploads, then device B must pull before the change appears. Sync both, then compare.
5. Custom WebDAV returning 404 / 405
That comes from non-standard protocol behaviour on the server side, and has its own fix: What to do about WebDAV 404/405 errors.
If the same entry is edited on two devices
Fields are resolved separately. If two devices changed different fields of the same entry — say a note on one and the password on the other — both edits survive.
Only when the same field was changed on both devices is there a choice to make, and then the later edit wins.
So if you change the password on your phone and the note on your computer at the same time, the two edits are not merged and the earlier one is lost.
This is a deliberate trade-off for now; we are measuring how often conflicts actually occur before deciding on field-level merging.
Suggestions
- Sync before making a batch of changes
- Avoid editing the same entry on two devices at once
One exception: when a deletion and an edit land at the same moment, the edit wins, so nothing is lost to a race.
Entry counts differ between devices
- Sync both and compare again — usually one side has not pulled yet
- Check the recycle bin: deleted entries go there and are excluded from lists. Its contents have no expiry and are never cleared automatically, so they can be restored at any time
- Check you are not on two different accounts (step 1)
The extension and the app show different things
The extension syncs passwords and 2FA codes. Documents, payment cards, secure notes and SSH keys live in the app only, so not seeing them in the extension is expected.