LG K40 Lagging / LG K30 Running Slow – How to Fix

LG K40 is a very capable phone with a decent 1.8 GHz Octa-Core CPU. LG Stylo 5 is equipped with the same Processor. However, the 2GB RAM on K40 is insufficient. On the other hand, K30 comes with a 1.4 GHz Quad-Core CPU and 2GB RAM.

Both K30 & K40 operate smoothly when new. However, over a period of time the storage space is occupied with Apps, Games, etc.  and slows down the phone. Other factors can also contribute to the slow performance of your phone.

In this post, we are going to find out the root cause and make your K30/K40 faster –

How to make LG K30 & K40 faster

1. Force Restart / Soft Reset

If your phone has slowed down (or frozen) all of a sudden, it must be a temporary issue & can be fixed with a Soft Reset. Use the power button to restart your phone.


lg k40 force restart

In case of a frozen screen, press the volume down & power keys for 10 seconds or until the phone restarts.

On LG K30, the power button is located on the back.

2. Reduce Animation Scale & Force GPU Rendering

lg k40 lagging


A very effective method to speed up your K30 & K40 is turning off the animation.

Open Settings & Go to the “General” tab.

Now scroll down and tap “Developer Options”.

If you’ve not yet enabled Developer Options on your K30 / K40, please check the below post –

LG K40 Developer Options

LG K30 Developer Options


how to make lg k40 faster

On the Developer Options page, Scroll down and look for the “Window Animation Scale”. The default value is 1x. Either turn off the animation or reduce the animation scale to 0.5x.

Do the same with “Transition animation scale” and “Animator duration scale”.


lg k40 running slow

I’ve turned off, Windows animation scale, Transition animation scale & Animator duration scale as marked above.

To reduce CPU load, you can turn on “Force GPU rendering”.




3. Free up the Internal Storage Space & RAM

a. Clear the Cached Data / Wipe Cache Partition

lg k40 running slow

Both K30 & K40 have 32GB internal storage space but only around half of the space is usable. As this available space keeps getting occupied, the phone performance is affected. It may also lead to a “Storage space running out” error.

To free up the internal storage space –

Go to Settings > General > Storage

lg k40 storage space running out

Select the first option i.e Free up space.

The “Temporary files” folder stores the cached data. You can also empty the “Download” & “Idle Apps” folder.

You can also delete other files stored in the Internal Storage folder.

There’s a dedicated post on the same –

LG K30 & K40 Wipe Cache Partition

b. Smart Cleaning


lg k40 smart cleaning

LG K40 has a special app that frees up the internal storage space & RAM.

Go to Settings > General > Smart Cleaning.


how to make lg k40 faster

Tap “Optimize phone”. This process deletes unnecessary files and stops unused apps.


c. Empty the Gallery Trash Can

LG K40 Trash can

Over a period of time, the deleted photos and videos keep on accumulating in the Trash folder. We should clean the trash can to make more space.

Open the “Gallery app” located on the home screen.

Tap the “3 dots” icon located on the top-right corner and select “Trash” from the dropdown list.


how to empty lg k40 trash can

Tap the “Delete icon” on the top-right corner and select the albums you wish to delete permanently.


lg k30 trash can

Tap “DELETE ALBUM” to empty the trash folder.

d. Delete Rarely Used Apps & Games

lg k40 delete apps

One more effective way to clean the storage space is by deleting unused apps and games.

Long-Press an app icon and drag it to the “Delete” button on the top.

For a detailed explanation, please follow the below link –

LG K40 Delete Apps




6. Safe Mode

lg k40 safe mode

Launch the Safe mode on your K30 /K40 & check the phone performance. If the phone is working fine in safe mode, some 3rd party app is slowing down your phone.

Detect the culprit app and uninstall it as per the below post –

LG K30 Safe Mode

LG K40 Safe Mode

7. System Update

lg k40 software update

Make sure your K30 / K40 is running the latest Android Software. Check out the below post to learn how to update your phone firmware –

LG K30 Software Update

LG K40 Software Update

8. Firmware Downgrade

lg k40 downgrade

If a recent Software Update has affected your phone performance, you can try to downgrade the Firmware. Learn how to Downgrade your K30 / K40 firmware using the LGUP flash tool –

LG K30 Downgrade

LG K40 Downgrade


9. Turn off Auto-Sync

lg k40 sync

If you receive too many emails, the auto-sync feature can slow down your phone.

Turn off “Sync” using the navigation panel shortcut as shown above.

10. Turn on Data Saver Mode

lg k40 data saver

The next solution to speed up your phone is enabling the “Data Saver” Mode.

It restricts apps to send and receive data in the background.

To turn on the “Data Saver”, Go to “Settings > General > Mobile Data.

lg k40 turn on data saver mode

Now, hit the “3 dots” icon on the top-right and tap “Data Saver”.

lg k30 data saver

Toggle on, Data Saver as shown above.


11. Remove any 3rd Party Launcher & Theme

lg k40 themes

A 3rd Party Launcher or Theme can also result in phone lagging.

Use the default launcher and Theme to speed up your K30/K40.

12. Factory Data Reset

lg k40 factory data reset

If all the above steps fail to make your phone faster, the final solution is the “Factory Data Reset”. During this process, the internal storage data will get erased. Please backup your phone data before doing a reset.

To learn how to reset your K30/K40, please follow the below post –

LG K30 Factory Reset

LG K40 Factory Reset

Which step worked for you? Please share your experience in the below comment section.


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