How to speed up a slow Android phone

A slow Android phone is usually short on free space, clogged with apps running in the background, or sitting on an update it never restarted to apply. The fixes below run from the fastest and safest to the most drastic: restart, update, clear out storage and cache, remove apps you do not use, trim the interface animations, track down a battery-draining app, and factory reset only if nothing else helps. Work down the list and stop as soon as the phone feels normal again. The menu paths use stock Android wording, and skins like Samsung’s One UI move some menus around, so treat the routes as a guide rather than an exact map.

Start with a restart, an update, and free space#

Three things fix most everyday slowness, and none of them costs you anything.

Restart the phone first. It clears out memory and stops any process that has been misbehaving since the last time the phone was on. It also matters for updates: Google notes that on many Android devices a downloaded update only becomes active the next time you restart, so a phone that feels sluggish after an update may simply be waiting for a reboot.

Next, make sure the system is current. Security and performance fixes ship in system updates, and you check for them under Settings > System > Software updates, following the prompts to install anything waiting. Google recommends being on Wi-Fi and charged before a large update, since these can take a while. See Google’s guide to checking and updating your Android version for the exact flow on your device.

Then deal with storage. A phone with almost no free space has nowhere to write temporary files, and it slows down as a result. Open Settings > Storage to see what is using space, and use Free up space to clear backed-up photos, downloads, and junk, per Google’s page on freeing up storage on an Android device. Our full walkthrough on how to free up storage on your Android phone covers the order that recovers the most room.

Clearing an app’s cache is the last of the quick wins. It is worth doing only on your two or three heaviest apps. Google draws the line between the two buttons plainly: clear cache “Deletes temporary data,” while clear storage “Permanently deletes all app data.” Use clear cache, which is safe; leave clear storage alone unless you are ready to set the app up from scratch.

Step	What it does	How drastic
Restart	Clears memory, applies pending updates	None; do it first
Install system updates	Adds performance and security fixes	None; can take time
Free up storage	Gives the system room to work	Low; you choose what goes
Clear app cache	Removes regenerable temporary files	Low; the app rebuilds it
Uninstall or disable apps	Stops their background work for good	Medium; you lose the app
Factory reset	Wipes and rebuilds the phone	High; last resort

Remove or disable the apps you do not use#

Every installed app can run work in the background, sync data, and hold a slice of memory, whether or not you ever open it. Thinning the herd is one of the most reliable ways to make an older phone feel quick again.

Start with apps you genuinely do not use and uninstall them. There is little to lose: Google points out that you can download an app again later, and you do not have to buy a paid app a second time. For preinstalled apps that will not uninstall, look for a Disable option on the app’s settings screen instead. Disabling hides the app and stops it running or updating, which frees up the same background resources even though the app stays on the phone.

Resist two temptations here. You do not need to swipe apps off the recents screen to save speed, because Android already suspends idle apps and reopening a force-closed one costs more work, not less. And third-party “booster” or “cleaner” apps mostly reclaim cache the system would clear on its own, while adding one more app to a phone that is already short on resources.

Ease off the interface animations#

Android plays a short animation every time you open an app, switch screens, or return home. On a fast phone you barely notice them; on a slow one they add up to a laggy feeling. Shortening or turning them off makes the interface feel close to instant, even though the underlying hardware has not changed.

The controls live in Developer options, which are hidden by default. Turn them on by opening Settings > About phone, finding Build number, and tapping it seven times until the phone confirms you are a developer. A Developer options menu then appears, usually under Settings > System. Inside it, scroll to the animation scale settings and lower them. Google’s developer documentation describes the two you want: Window animation scale and Transition animation scale, noting that “A lower scale results in a faster speed.” Set each to a lower value, or to off, and back out.

Setting	What it controls	Set it to
Window animation scale	The animation when a window opens	0.5x or off
Transition animation scale	The animation when screens change	0.5x or off

This is safe to change and just as easy to undo: return to the same screen and set the scales back to 1x if you miss the motion. Full details are in Google’s on-device developer options reference.

Track down a battery-draining app#

A single app stuck running in the background can drain the battery, heat the phone, and drag performance down as the system throttles a hot device. Finding that app is worth the two minutes it takes.

Open Settings > Battery and look at the per-app battery usage list, which ranks what has consumed the most power since the last full charge. If one app you rarely use sits near the top, that is your suspect. Tap it and set its background usage to the restricted or optimized option rather than unrestricted. Google recommends keeping Adaptive Battery and the “Optimized” default on, so the system can quiet down apps you open less often on its own. Our guide to saving battery on an Android phone goes deeper on Adaptive Battery, Battery Saver, and which “tricks” do nothing. If restricting one app calms the phone, you have found the problem without wiping anything.

Factory reset, only as a last resort#

If a phone is still slow after all of the above, a factory reset returns the software to its original state and clears out whatever has accumulated. It is genuinely a last resort, because it erases everything on the phone. Google itself recommends trying other solutions before resetting to fix a problem.

Back up first. A factory reset uninstalls all your apps and their data, and only what is saved to your Google Account or another backup can be restored afterward, so confirm your photos, contacts, and files are safe before you begin. On most phones the path is Settings > System > Reset options > Erase all data (factory reset), described in Google’s page on resetting an Android device to factory settings. Because the stakes are high, walk through our steps on how to factory reset an Android phone safely so the backup and sign-in are handled in the right order.

Most phones never need the reset. Restarting, updating, clearing space, cutting a few background apps, and trimming animations handle the great majority of slowdowns, and they take minutes rather than an afternoon. Run through them in order the next time the phone drags, and keep the reset in reserve for the rare case where nothing else moves the needle.