Back in September 2013, YouTube announced it would be adding offline viewing to its mobile apps. However, that didn't happen. Last year it finally followed that up with the launch of  YouTube Go, an official app for downloading videos in countries where mobile data is too expensive for streaming them.

There's also a premium service (the creatively named YouTube Premium) that allows users in certain countries - including the UK and US - to download YouTube content to later watch offline.

The only problem is that YouTube Premium is a paid-for service. If you're going to download videos regularly it's arguably worth the cost - £9.99/US$9.99 per month - but if you just want to download an occasional clip it might not be worthwhile. The good news is that it's easy to download YouTube videos on your computer, and here we'll show you how to save them to your PC, smartphone or tablet.

For the ethics and legality of doing this, see our guide to whether it's legal to download YouTube videos. But suffice to say, if you're downloading video for your own viewing only then you shouldn't have anything to fear.

Jump straight to the section you need:

Download using YouTube Premium

If you're a YouTube Premium subscriber then downloading videos is easy. There is one big caveat though: you can only do it using the official YouTube or YouTube Gaming apps, which means you can't use Premium to download videos to your computer - only to a phone or tablet.

To download simply open the app and head to the video you want to download. Underneath the player you should see a 'Download' icon - tap that, pick what video quality you want to download, and that's it.

Once the video has downloaded the icon below it will change to blue tick - tap this if you want to remove the download. You'll be able to find all your downloaded videos in the Library or Account tabs.

Download videos using a web browser

If you want to download YouTube videos directly to a computer, the easiest way is usually through your browser. Although there are video downloader plugins for certain web browsers, the easiest way to download is to copy and paste the URL of the video you want into a website.

There are many that offer this service for free, but they often get shut down.

One that works currently is DLNowSoft., which is free and has no adverts on it. This should work directly through the site or as a separate program for more secure downloads.

Another option is VidPaw. You can either copy and paste your YouTube video URL, or simply add the word 'paw' after youtube in the original url to go to the download page. We found that you can't always download the highest resolution, so the video below is limited to 720p despite the original being in 1080p.

However, both these sites have a policy that restricts you from downloading copyrighted content, such as music videos. 

Download YouTube videos from web browser

If for some reason MP4 video isn't suitable for your needs then Freemake Video Converter can convert the downloaded videos into other formats. You could alternatively use ClipConverter, a free online tool that downloads YouTube videos and converts them into the format of your choice in one go.

To use a website such as DLNowSoft or ClipConverter, this is the process:

1. Head to www.youtube.com and find a video you want to download. Copy the URL from your browser's address bar. Clicking in the address bar is usually enough to highlight it, but clicking three times should also do the job. Press Ctrl-C to copy the highlighted address.

2. Now go to the video downloader website. Put your cursor in the box for the video URL and press Ctrl-V to paste your copied address. If there are options, such as resolution or format - such as MP4 or MP3 (which is audio only) - choose what you want and click Download.

4. Look in your ‘downloads’ folder to find the video file. You can also copy the file to another computer or transfer it to another device (here's how to convert videos for free using Freemake and Any Video Converter.)

Download using a Windows app

As with websites, there are lots of options for downloading with a desktop app. Not all are free, but some are. A paid-for one we particularly like is YouTube ByClick (see below). If you want a free option, try WinX YouTube Downloader. This will nag you to upgrade to the full version which includes conversion to other formats (including MP3), but if you can put up with these, it won't cost you anything.

How to download YouTube videos

The process is virtually identical to using a website: you copy and paste the URL of the video into the app. Then you choose any options, such as the resolution to download, then hit the Download button. Most apps allow you to build up a list of videos and then download them in one go. Some even let you paste in a YouTube playlist and automatically download all the videos.

Others are time-limited demos, such as DLNow Video Downloader, which gives you a 30 day trial. That's longer than YouTubeByClick which only lets you try it for 24 hours.

Download YouTube playlists

Sometimes you have to pay for software if you want an easy life. YouTube ByClick makes it supremely easy to download video - or just audio - from YouTube. All you have to do is to copy the URL of a video and a pop-up will ask if you want to download the audio or video. Or you can set a default and it won't even ask: it will automatically download the MP3 or MP4 at the default quality.

If the video is part of a playlist you can click the 'Download playlist' button and you'll get a pop-up like the one shown below where you can choose which videos you want from the playlist. A single click on the Download button is all you need after that.

You get a day's free trial to see if you like the program, but after that you'll have to stump up some cash. Currently, it's half price at $9.99.

How to download YouTube Playlists

Download music from YouTube

Sometimes you might want to download only the audio from a video on YouTube. The easiest way to do this is to use one of the above browser services like ClipConverter and set the format to MP3 - this way you'll only download the audio track, with none of the video footage - perfect if you just want to download some music or the audio from a YouTube podcast.

It's worth noting that you can also download music as part of YouTube Music Premium, a service that's slightly cheaper than regular YouTube premium - just £9.99/$9.99 per month. It will let you download songs and even music videos, but is limited to music - you won't be able to download other videos.

Download videos to a smartphone or tablet

Beyond the official YouTube Premium service, there are other apps which allow you to download videos directly on your Android phone, but it's trickier on the iPhone. We've written separate guides for these:

But don't forget you can download the files on your PC or laptop using the methods above then copy them to your phone or tablet.

For Android devices, simply copy the MP4 files(s) to the appropriate folder, typically Movies, using File Explorer. You can then play it back using the Gallery app or another video player.

If you have an iPhone or iPad, import the file into iTunes and then sync it to your iOS device. Alternatively, you can drag and drop the file(s) to your iPhone or iPad via the Apps tab when you click on your device in iTunes. All you need is an app, such as Good Reader or another video playback app which can transfer files using this method.

If you don't want to use iTunes and you're happy to pay, Waltr 2 is an excellent little utility for copying videos, music and other files to your iOS device so they appear in the native apps. Find out more in our guide to transferring videos to iPad and iPhone.

Finally, here's how to download any online video - not just YouTube.