On the Pixel 9 Pro, sync is run by the Google account, and when contacts, calendar, photos or app data stop updating, the cause is nearly always a switch, a background limit, a storage limit or a sign-in prompt, not the phone. Open Settings, Passwords, passkeys and accounts, tap your Google account, then Account sync, and look at each data type and when it last synced. A type that is turned off will not update, and one that shows an old time is blocked. Tap the three dots, Sync now.
The checks in more detail
If a type shows a problem, such as an error about sync, check the connection, then look at Settings, Network and internet, Data Saver, which can block background data. The Pixel 9 Pro has a large battery, but Battery Saver and Extreme Battery Saver pause sync, so check they are off. Adaptive Battery on a Pixel learns your habits and can restrict apps you rarely open, so a mail or notes app may sync late; open Settings, Apps, choose the app, App battery usage and choose Unrestricted for a test.
For Google Photos, check that Back up is on and that the account is the right one, and look at the storage: the account's 15 gigabytes of free storage is shared by Gmail, Drive and Photos, and a full account stops backups, so check at one.google.com. If the account says that you need to sign in, remove it from the phone and add it again; make sure first that the data is safe in the cloud.
The Pixel 9 Pro gets updates quickly, and an old build can have sync bugs, so install updates from Settings, System, Software updates. Check the date and time are automatic, since a wrong clock breaks sign-in. If one app, such as Google Calendar, fails while the rest work, clear that app's cache and open it again. A Pixel with a work profile may follow the employer's sync policy. Restart the phone. As a last resort, a factory reset after a complete backup will rebuild the account. Google's help pages and the Pixel Tips app can also guide you.
Differential
Likely causes of “Google Pixel 9 Pro photos, contacts, messages or account data will not sync”, and how to tell them apart
- 1
A sync switch that is off
What separates it One data type stops updating
How to confirm Turn it on and tap Sync now
- 2
Battery Saver or Adaptive Battery limits
What separates it Sync is late
How to confirm Turn off Battery Saver and set the app to Unrestricted
- 3
Data Saver blocking background data
What separates it Updates arrive only when the app is open
How to confirm Allow the app to use data in the background
- 4
A full Google account
What separates it Photos and Drive stop saving
How to confirm Clear or buy storage
- 5
An account that needs a sign-in
What separates it A prompt appears
How to confirm Remove and add the account again
Before you touch a setting
Record this first — changing settings destroys the evidence
- Which data type fails
- The last synced time
- Whether Battery Saver is on
- The account storage figure
Try in this order
0 of 6 completedOpen Account sync
ReversibleAnd tap Sync now.
Turn off Battery Saver
ReversibleAnd Data Saver as a test.
Set the app to Unrestricted
ReversibleIn app battery usage.
Check Google storage
ReversibleAt one.google.com.
Re-add the account
ReversibleIf it asks.
Update and restart
ReversibleThe phone.
Model-specific
What is true of this model and not of its siblings
- Shared storage
- Gmail, Drive and Photos share the quota.
- Adaptive Battery
- It can restrict rarely used apps.
Stop boundary
When this stops being a self-service repair
- !If sign-in fails, use the Google account recovery page
- !If one app fails, contact that app's support
- !Back up before a reset
Evidence ledger
Sources behind this answer
Exact questions
Common questions
Why is my Pixel 9 Pro not syncing?+
A switch, a battery limit or a full account.
Does Battery Saver stop sync?+
Yes.
How much free Google storage is there?+
15 gigabytes shared across Gmail, Drive and Photos.
Should I reset?+
Only as a last step.