Microsoft To Do not updating: get tasks syncing again

When Microsoft To Do stops updating, the usual cause is a sync delay, a sign-in mismatch, or stale app data on one device. Start by confirming you’re signed into the same Microsoft account everywhere, then force a refresh before you try anything more invasive. If that doesn’t fix it, the next checks depend on whether the problem shows up in the web app, Windows, iPhone, or Android.

What it looks like when Microsoft To Do stops updating

You add or edit a task on one device, but the change does not show up on another.

This can show up in a few different ways. A task may appear only after a long delay, an old task may stay on one device after you deleted it elsewhere, or the web app may update while the mobile app stays stuck.

That difference matters. If the same task updates in one place but not another, the account is often fine and the problem is local to one device, one browser, or one app install. If nothing updates anywhere, the issue is more likely with your sign-in, connectivity, or Microsoft’s own sync service.

Before you start

This applies to Microsoft To Do on the web, Windows, iPhone, and Android. The fixes below do not require Administrator access or sudo, and they are meant to be safe on an active account.

You do not need to back up anything to try the early steps. Still, before you clear cache, sign out, or reinstall, make sure you can see your tasks in the web app or on one other device so you know the data is still there.

Do these two checks first:

• Confirm the same Microsoft account is signed in everywhere.
• Make sure the device has a working internet connection before you assume To Do is broken.

Why this happens in the first place

The most common cause is being signed into different Microsoft accounts on different devices. Microsoft To Do only syncs tasks across the account that owns them, so a work account, personal account, or school account mix-up can make it look like tasks vanished.

Other common causes are less dramatic: a weak or blocked internet connection, the app being offline for a while, cached data that has gone stale, or a sync delay on Microsoft’s side. Outlook and Microsoft 365 can also be part of the picture, especially if the tasks came from Outlook Tasks. In that case, a problem in Outlook syncing can show up as a To Do problem even when the To Do app itself seems fine.

If only one device is affected, suspect that device first. If every device shows the same stale view, suspect the account or service layer first.

The quickest fixes to try first

Start with the safest checks. They do not risk task loss, and they often solve the problem.

1. Check that you are signed in with the same Microsoft account everywhere. Look at the account name or email address in the app, on the web, and on each device. If one place shows a different account, switch it before doing anything else. If you have both a personal Microsoft account and a work or school account, this is the first place things usually go wrong.
2. Make sure the device is online. Open a website or another app that needs the internet. If that fails too, the problem is not Microsoft To Do. Fix the connection first, then return to To Do.
3. Force a refresh. In the web app, refresh the page in your browser. On mobile, close the app completely and open it again. On Windows, quit the app from the taskbar or system tray if it is still running, then reopen it.
4. Wait a short while after edits. A small sync delay can happen. If you just changed several tasks, give it a bit of time before assuming it failed.

If the task appears after a refresh, the issue was probably just a temporary sync lag or a stale screen. If nothing changes, move on to the device-specific checks below.

If one device updates but another one doesn’t

If a task added on your phone shows up on the web but not on your desktop, the desktop app or browser is the likely problem. If the reverse happens, focus on the phone. That pattern usually means the account is fine and only one client is stuck.

Web app

Open Microsoft To Do in a private or incognito window and sign in again. If the task appears there, your normal browser cache or cookies are probably holding old data. Then clear the browser cache for the To Do site and reload it.

Browser settings > Privacy and security > Clear browsing data

If the private window also shows stale data, the issue is less likely to be a browser cache problem and more likely to be account-related or on Microsoft’s side.

Windows app

The Windows app can hold onto stale local data even when the account is fine. Fully close the app, then reopen it.

Windows > Settings > Apps > Installed apps > Microsoft To Do > Advanced options

If it still refuses to update, check whether Windows is blocking background activity or whether the app is signed into the wrong account. If only the Windows app is stuck and the web app looks current, the problem is probably local to that install.

iPhone

On iPhone, the app can look current while the underlying sync is stuck. Open the app, switch between lists, and then close it from the app switcher before reopening it. If you use Low Power Mode or have limited background refresh, that can also slow updates.

iPhone > Settings > General > Background App Refresh

If the web app updates but the iPhone does not, the phone is the place to focus.

Android

On Android, a battery saver or background restriction can keep the app from syncing properly. Open the app settings and check whether background data is allowed. Then reopen Microsoft To Do and see whether the missing task comes through.

Android > Settings > Apps > Microsoft To Do > Mobile data & Wi-Fi

If one device is always the odd one out, treat it as a local app problem first. If every device disagrees with the web app in the same way, the account or service side is more likely at fault.

When to sign out, clear cache, or reinstall

If the safer fixes did not help, move to the next level in a controlled way. The point here is to remove stale local data without assuming the account itself is broken.

Before you clear anything, confirm the same Microsoft account is used on at least one other working device or in the web app. That way you can tell the difference between a local app issue and a real account-wide sync problem.

1. Sign out and sign back in. Do this on the problem device or browser first. On sign-in, the app should pull a fresh copy of your tasks. If the missing task appears after sign-in, the issue was probably local session data.
2. Clear the app or browser cache. On the web, clear cached site data for Microsoft To Do or the browser cache if the problem is broader. On mobile, use the app’s storage controls if available, or reinstall the app after you have confirmed your tasks are visible elsewhere. On Windows, clearing the app’s local data can help if the app is stuck on an old local state.

Browser settings > Privacy and security > Site data > Microsoft To Do

Windows > Settings > Apps > Installed apps > Microsoft To Do > Advanced options > Reset

3. Reinstall the app if needed. This is usually the last step, not the first. Reinstalling removes the local app state and gives you a clean start, but it does not fix a wrong account or a service-side sync issue by itself.

Reinstalling is a cleanup step, not a repair for account-level sync problems. If the web app and another device are both stale, reinstalling the app alone probably will not help.

If the app still will not update after all that, the problem is probably not just the device. At that point, compare the web app, Outlook Tasks, and another device. If all three are stale, the issue is likely farther upstream than one phone or one PC.

How to make sure it’s really fixed

The easiest way to verify the fix is to create one small test task in the place that was not updating. Give it a unique name so you can spot it easily, such as “sync test” or “do not delete test.” Then open Microsoft To Do on another device or in the web app and check whether it appears there.

If the fix worked, the task should show up after a short refresh without any extra changes from you. Edit the test task once, then confirm the edit appears on the second device too. That tells you the problem was not just a one-time display glitch.

If the test task still does not appear, stop making more edits on the problem device until you figure out which side is lagging. That keeps the test clean and makes it easier to tell whether the issue is local, account-related, or tied to Microsoft 365 or Outlook sync.

Conclusion

If Microsoft To Do is still not updating after these checks, focus on the one device that stays out of sync and compare it with the web app. If the web app also looks stale, the problem is likely account or service related rather than a bad install. Create one fresh test task, check it on a second device, and use that result to decide whether to keep troubleshooting the app or move on to Outlook and Microsoft 365 sync.

Frequently Asked Questions

Why do my Microsoft To Do tasks show on one device but not another?

That usually means one device is using stale app data, a different Microsoft account, or a browser/app session that has not refreshed. Start by checking the account name everywhere, then force a refresh on the device that is lagging.

Does Microsoft To Do sync with Outlook?

Yes, tasks can be affected by Outlook and Microsoft 365 sync, especially if they came from Outlook Tasks. If Outlook is out of sync, Microsoft To Do can look stale even when the app itself seems normal.

Will reinstalling Microsoft To Do delete my tasks?

Your tasks are stored in your Microsoft account, not just on the device, so reinstalling usually does not delete them from the account. Still, check that the tasks are visible in the web app or another device before removing the app from the problem device.