WhatsApp for Samsung Galaxy J5 (2016)

Yes, WhatsApp has dropped support for Android 5.1 and older, so a J5 (2016) still on its original Lollipop firmware will eventually stop getting updates and may stop working. Check your version under Settings > About device > Software info, and if a 6.0 Marshmallow update is offered under Settings > Software update, install it (the J5 2016 did receive Marshmallow) to extend WhatsApp compatibility. Once support fully ends, back up your chats via WhatsApp > Settings > Chats > Chat backup and move to a newer phone. See how others solved this on Reddit

WhatsApp normally quiets phone alerts while a Web session is active, but if both keep notifying, open WhatsApp on the phone and go to Settings > Notifications to turn off the alerts you don't want. You can also silence it at the system level via Settings > Applications > WhatsApp > Notifications, or just lock the phone and set it aside while you use WhatsApp Web on the desktop. See how others solved this on Reddit

WhatsApp media is the usual culprit on the J5's 16GB storage, so open WhatsApp > Settings > Storage and data > Manage storage and delete large videos and forwarded files first. Then go to Android Settings > Storage and clear cached data, and move photos to a microSD card via the My Files app. The J5 (2016) has a microSD slot, so insert a card and set it as the camera and download location to keep internal storage from filling up again. See how others solved this on Reddit

First confirm WhatsApp has microphone access under Settings > Applications > WhatsApp > Permissions, then gently clean out the small mic hole on the bottom edge near the charging port, since lint can muffle it. If it still fails, test the mic with a normal phone call or a voice recording to isolate hardware faults, restart the device, and clear WhatsApp's cache via Settings > Applications > WhatsApp > Storage > Clear cache. See how others solved this on Reddit

It can still handle basic WhatsApp messaging and calls, but the aging battery, 16GB storage and outdated Android version mean voice notes, video calls and app updates will feel sluggish or break over time. If you mostly need texting and the odd call it still works, but keep chats backed up to Google Drive (WhatsApp > Settings > Chats > Chat backup) so you can migrate easily once WhatsApp drops this Android version. See how others solved this on Reddit

On the J5's 2GB of RAM, clear WhatsApp's cache under Settings > Applications > WhatsApp > Storage > Clear cache, then free memory by closing background apps and disabling bloatware you don't use under Settings > Applications. Keep the app updated via the Play Store and the system updated under Settings > Software update. If crashes persist, the limited RAM is simply being maxed out, so a lighter chat load or fewer running apps is the only real fix. See how others solved this on Reddit