Android Reminders Not Working? Fix Notification & Battery

If your Android reminders are not working, the cause is almost always a combination of notification permissions and battery optimization settings that are silently blocking the reminder from appearing. This guide walks you through the exact settings to check and change, in order, so your reminders fire reliably again.

Why Android Reminders Fail Silently

Android is designed to aggressively save battery by putting unused apps to sleep. When an app that manages reminders (like Google Keep, Todoist, or your default calendar app) is optimized for battery, the system can delay or completely stop its background activity. This means the app never wakes up to post the notification at the scheduled time. Additionally, each app has its own notification channel—a separate toggle for reminders versus other alerts. If that specific channel is disabled, you won’t see the reminder even if the app itself has notifications turned on.

Step 1: Check App Notification Permissions

Start with the most obvious setting. For each reminder app you use, verify that notifications are allowed at the system level.

Open Settings > Apps (or App management).
Tap the app that handles your reminders (e.g., Google Keep, Google Calendar, or any third-party to-do app).
Tap Notifications.
Make sure the top toggle Show notifications is on.
Scroll down to the Reminders (or Alerts) category and ensure it is also enabled. Some apps have separate toggles for “Reminders” and “Other notifications”.

If you previously tapped “Block” on a notification preview, that might have disabled the entire channel. Re-enable it here.

Step 2: Disable Battery Optimization for the App

Battery optimization is the most common hidden culprit. Android’s Doze mode and App Standby can prevent your reminder app from running in the background, so it never delivers the notification on time.

Go to Settings > Apps > select the reminder app.
Tap Battery (or Battery usage).
Tap Battery optimization (or Unrestricted / Allow background activity depending on your Android version).
Choose Don’t optimize (or Unrestricted) for that app.

On Samsung devices, the path is Settings > Apps > select app > Battery > Background usage limits > select Unrestricted. On Xiaomi/Redmi, look for Autostart permission and enable it as well. On OnePlus, go to Settings > Battery > Battery optimization and select the app.

If you have a custom “battery saver” or “ultra power saving” mode active, that can also block reminders. Turn those off or exempt the app.

Step 3: Verify Date, Time, and Time Zone

Reminders are tied to your device’s clock. If your time zone is wrong or your clock is set manually and drifts, the reminder will fire at the wrong time or not at all.

Go to Settings > System > Date & time.
Enable Use automatic date & time and Use automatic time zone.
If you travel, make sure the time zone updates correctly. A manual override is a frequent cause of missed reminders.

Step 4: Check the Reminder App’s Own Settings

Many reminder apps have an in-app setting that controls whether reminders are delivered as a notification, an alert, or an email. For example, Google Calendar has a default reminder time and a notification sound. If the app’s own reminder channel is set to “None” or “Silent”, you might get no visible alert.

Open the app and go to its Settings.
Look for Reminders, Notifications, or Alert defaults.
Set the default reminder time (e.g., 10 minutes before) and choose a sound or pop-up.
If the app has a “Notification sound” option, pick one—”Silent” can make it easy to miss.

Step 5: Clear App Cache and Data (as a Last Resort)

Sometimes the app’s internal data gets corrupted, causing reminders to stop firing. Clearing the cache is safe and often fixes the issue. Clearing data will reset the app to its defaults—you’ll lose any in-app settings but not your reminders if they are synced to your Google account.

Go to Settings > Apps > select the app.
Tap Storage.
Tap Clear cache first. If that doesn’t help, tap Clear storage (or Clear data).
Reopen the app and sign in if needed. Your reminders should reappear from the cloud.

Step 6: Update the App and Android System

Bugs in the app or the Android system can break notifications. Check for updates:

Open the Play Store, tap your profile icon, then Manage apps & device > Update all.
Go to Settings > System > System update to check for Android OS updates.
Restart your phone after updating—this clears temporary system issues.

Frequently Asked Questions

Why do my reminders work in the app but not as notifications?

This is almost always a notification channel issue. The app might have notifications enabled globally, but the specific “Reminders” channel is turned off. Go to the app’s notification settings and enable the reminder category. Also, check if your phone’s “Do Not Disturb” mode is scheduled—that can suppress all notifications.

Does battery saver mode block reminders?

Yes, battery saver mode can delay background activity and notifications. When battery saver is on, Android may restrict apps from running in the background. You can either turn off battery saver or add the reminder app to the “Unrestricted” list in battery settings.

My reminders only fail when the phone is locked. Why?

When the screen is off, Android’s Doze mode kicks in. If the app is not set to “Unrestricted” in battery optimization, Doze will prevent it from waking up to deliver the notification. The fix is to disable battery optimization for that specific app.

Will clearing app data delete my reminders?

If your reminders are synced to your Google account (which most reminder apps do), clearing data will not delete them—they will re-download when you sign in. However, if the app stores reminders only locally (no account sync), clearing data will erase them. Always back up or verify sync before clearing data.

Why do my reminders work on Wi-Fi but not on mobile data?

This is rare but can happen if your mobile data settings restrict background data for that app. Go to Settings > Apps > select app > Mobile data & Wi-Fi and ensure Background data is enabled. Also check if your carrier’s data saver mode is blocking background network access.

Do I need to keep the reminder app open in the background?

No, you don’t need to keep it open, but it needs to be allowed to run in the background. If you swipe it away from the recent apps list, some aggressive OEMs (like Xiaomi or Samsung) will kill it. Add the app to the “Never auto-close” or “Lock” list in your recent apps menu to prevent that.

General steps for current mainstream versions; menus can differ by device and version. See the disclaimer or report an error.

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