You can do a few things, first look at your storage and see if perhaps you are running out of space. If you are, either insert an SD card and move excess data (photos, documents) to the SD card (or delete what you don't need) and then direct your photos and downloads to save to the SD card. My Files/manage storage. Empty the trash, look at the analytic graph to see what's taking up space. If you find you have plenty of space available. You can try wiping the cache partition to get rid of old bits and pieces. To delete the cache partition, power down your phone. Restart the phone by holding the power and volume up buttons until you see the Samsung Galaxy logo appear on the screen. Let go of the power button, then the volume button and allow the phone to enter recovery mode (it may take a minute). When you are in recovery mode, use the volume up/down buttons to navigate. Navigate to "wipe cache partition" and press the power button to select. After reading the warning, navigate to "yes" and press the power button. The cache will wipe and "reboot" will be highlighted. Press the power button to reboot. After the phone fully reboots and sets up, go to Device Care and run the optimization tool. Then set your phone to auto optimize and choose which option for restarting you want: schedule or when needed. Also, download Good Lock from the Galaxy store and then download the Galaxy App Booster module and run that (it will take a long time, but you can still use your phone). Any one or all of these things should speed up your phone. Also download Good Guardian's Thermal Guardian module to make sure you are not having periods of overheating, which will also slow down your phone. Minimize the amount of apps allowed to run in the background (battery/background usage limits). You can also restrict apps individually from running in the background by going to the app settings and tapping on "battery" and selecting whether or not to limit background usage.
