Your Android smartphone/device is a computer. Like most computers, it can get slow after a while and benefit from a periodic cleanup. Here are some things you can do to speed up your Android phone if it's acting slow:
Maybe this is obvious, but if you haven't powered off your phone in a while, go ahead and reboot it (or power it off and back on again).
- (Nexus and HTC One phones only) Try LagFix
This only applies if you have a Nexus or HTC One phone and running Android less than 4.3. These devices have a very specific bug that causes lag and can be fixed by this app: LagFix (fstrim) Free (requires root). I wouldn't recommend running this for other phones; at best it will do nothing and at worst it could damage your phone.
- Undo any recent changes
If your phone has only recently been acting slow, think about any recent changes you've made. Have you recently installed or updated certain apps? Have you recently received a software update? Any of these changes can slow your phone down. If it's an updated app, you can sometimes find old versions of apps online. If it's a software update, undoing it will be much trickier, but it is possible. If it is indeed the culprit, somebody's probably written up instructions on how to go back to the previous software version.
- Uninstall/disable unused apps
Some apps actually run in the background whether or not you've opened them. Too many of these kinds of apps will definitely slow down your phone. Examples of apps that run in the background are apps that display notifications, whether notifications that are always present or notifications that show up from time to time. Aside from these, we could certainly all benefit from going through our apps from time to time and removing any we don't use any more.
Some phones come with a lot of preinstalled apps that you don't use or want (called bloatware). These often can't be uninstalled, but they can be disabled starting in Android 4, which should at least keep them from slowing down your phone. To disable them go to Home Menu System settings Application manager All, select the app to disable, and click Disable.
I intentionally put this step after the previous step, because the first step really is to get rid of apps you're not using. But of course there are certainly some apps that you'll want to keep, and what if one of those is the culprit, running in the background and slowing your phone down? Thankfully there's a great solution: Greenify. It's an app that lets you control which apps run in the background. It doesn't kill them, but it hibernates them instead. Because of this, it does need root access.
Side note: I mentioned that Greenify doesn't kill apps running in the background. This is because killing apps can actually slow your phone down and use up your battery faster because then the apps will just start themselves back up. If you're using a task killer app thinking you're speeding your phone up or saving battery life, you're probably doing just the opposite. You should uninstall it right away, and instead follow the steps in this post if you're having issues.
- Remove some widgets
Building on the previous point, there's a whole category of software that runs in the background: widgets. Any widget you have on your home screen is going to run in the background on your phone all the time. The more you have, the slower your phone can get. Remove a few and you may notice your phone runs faster.
- Don't use live wallpaper
Live wallpaper is fun, but it's just creating extra work for your phone and using up your battery faster. Use regular wallpaper instead.
- Look at your SD card
If your phone has a removable SD card, turn it off and remove it. See if that fixes the problem. If so, see what the speed class of the card is. If it's less than class 6, I'd recommend buying at least a class 6 card, especially if you've moved any of your apps to the SD card. If your phone has internal storage, which most recent phones do, you could even try running without the SD card. At the very least go through your SD card and clean up some of the unused files and folders. Apps have an annoying habit of putting things on there and not cleaning them up.
- Clear app cache
Clearing the caches for your apps may help speed things up. If your phone is rooted and Titanium Backup is installed:
- Open Titanium Backup
- Go to Menu → Batch actions
- Scroll down to Manipulate data → Clear cache for user & system apps and click RUN
- Click Select all and then click the green check mark in the upper right to begin the task
If your phone isn't rooted and/or you don't have Titanium Backup installed, the process is a lot more tedious:
- On your phone, go to Home Menu System settings Application manager All
- For each application in the list, select it and click Clear cache. Yes, I told you it would be tedious. This should be good incentive to follow my previous suggestion at getting rid of unused apps :)
- Wipe cache partition
This will probably only be available to you if you've rooted your phone. If you have, power it off, boot into recovery mode (varies by phone), and select the option to wipe the cache partition.
- Disable/uninstall apps one by one
I've saved this one towards the end because it's going to be pretty tedious. If you've made it this far and your phone is still inexplicably slow, you can try disabling or uninstalling apps one by one and seeing if that changes anything.
- Factory restore
I wouldn't recommend doing this more than once a year, because you're going to have to set your phone up from scratch after doing it, but just like formatting your computer and reinstalling everything, a factory restore can help speed up your phone. First, back everything up (I recommend rooting it and using Titanium Backup). Once you've backed everything up, you can do the factory restore by going to Home Menu System settings → Backup and reset → Factory data reset (specific location varies by device). Again, in case you weren't paying attention, this will erase everything on your phone, so make sure you've backed up everything that's important first.
- Downgrade Android
Sometimes the device manufacturers release software updates that end up making the phone slower. The solution in this case is to downgrade Android. This is not a trivial task, and will vary by device, so you'll have to Google this one. Honestly if you get to this point, you may just be better off buying a Moto G.