Many cheap Android phones come with a paltry 4- or 8GB of storage, while even 16GB isn't really enough for lots of apps, high-resolution photos and videos, plus a music library. Fortunately, the vast majority of Android phones have a memory card slot, into which you can slot an inexpensive microSD card.

What you need to know about microSD cards

Before you buy one, check what capacity your phone will support. Flagship phones tend to accommodate 128GB or higher, but many cheap Androids accept only 32GB. To be fair, 32GB will be enough for most people. We've tested and rated all the best microSD cards

Once you've got the microSD card, it's easy to set things up so that it becomes the default place for new apps, photos, videos, music and more. You can switch the storage location within your camera settings or Google Play Music settings, for example. But what about the stuff already clogging up your phone's internal storage?

How to move apps to SD card

First, let's clear up something important: not all apps can be moved to microSD, and some phones won't let you move apps to SD at all. This means phones with just 4- or 8GB of internal storage can still run into problems even with a microSD card if you download and use a lot of apps.

Whether or not an app can be moved to microSD is down to the app developer and, sometimes, the phone manufacturer. 

The Galaxy S8 is one of several phones that does allow you to move apps to SD, but you should note that those apps won't be available when you remove the SD card. The screenshots below have been taken on a Galaxy S8 and may look a little different to what you're seeing on your own phone, but the process should be largely the same.

To move an app to the SD card select it in the Settings, Apps menu, then tap on Storage. If you are able to move the app to SD you will see a 'Change' button next to Storage used: Internal shared storage.

Can I move an app to SD?

Here we've selected BBC iPlayer, which was not preinstalled on the phone and can be moved (preinstalled apps often cannot be moved). Also note our screenshot of Bixby Voice, however, which lacks this Change button and therefore can't be moved.

To move an app to SD tap the Change button and select the SD card option in the pop-up menu. You'll see a screen offering to export the app, warning you that you shouldn't remove the SD card while this is in progress. Tap Move. The transfer will then take place.

Move apps to SD on Galaxy S8

Move to SD card greyed out

In older versions of Android you may find the option to Move to SD card will be greyed out, as is the case with the Amazon Music app that is preinstalled on this EE Harrier Mini. These apps cannot be moved to microSD.

Can't move to SD

It's worth pointing out that many free apps are available that offer to automate this process for you. If you're concerned about storage then adding yet another app probably isn't the best idea, but you can always uninstall it once it has done its job.

Format SD as internal storage

Note that some phones require you to set the SD card as internal storage first, before you can migrate any data. The HTC U11 is an example so you'll need to find the microSD card in the storage section of the settings menu and 'Format as internal'. The process will be similar on other phones.

How to move photos, video, music and files to SD

The easiest method of moving files to SD is browse to Settings, Storage on your Android phone or tablet, then look for an option to 'Transfer data to SD card'. Not all Android devices have this option, and if yours doesn't you'll need to manually move the files. 

The second easiest way to quickly move photos, video, music and other files to a microSD card is to do so using a PC or Mac. Hook up the phone to your computer via a USB cable, then open a new window to browse its contents.

You should be able to see the phone's internal storage and SD card as two separate storage devices. We're using Android File Transfer on a Mac, which shows the Internal storage and SD card on separate tabs. 

To move files from Internal storage to SD card simply drag-and-drop files to copy them from the internal storage to the Mac desktop and back to the phone's SD card, then delete them from the phone's internal storage. Just don't try to move any Android system files.

SD on Mac

File manager app

Another option is to use a File manager app. Many Android phones come with such an app preinstalled, but it is not a standard part of Android. We've downloaded the free File Manager app from Topnet999, but ES File Explorer is another popular app.

Tap on the Storage tab at the top of the app to see the various storage available on the phone. Here sdcard0 was our phone's internal storage, while sdcard1 was the microSD card. Let's start with photos.

First open sdcard0 and browse to DCIM, Camera. Here you'll find any shots taken by your camera. Tap the three dots at the bottom right of the screen and choose Multi-select. Tap on each item you want to move to SD; when selected the white text becomes yellow. Now choose Move, browse to the microSD card and choose Move here. 

Repeat the process for any music and other files stored on your device.

If you're phone's due for an upgrade, check out the best new phones coming in 2017

Follow Marie Black on Twitter.