Since August, when we last updated this How To, YouTube has changed its terms and conditions to prevent any app from downloading videos to watch offline. There also seems to be a change in iOS 8 which removes the 'download' pop-up as all the apps we've used in the past have now lost their download option. When we find a solution, we'll update the article again.
The reason for the change is because YouTube is finally introducing offline watching, which is set to be added to the official YouTube app in November 2014.
There is a workaround until that happens, but it involves downloading the video via your PC or Mac, and then copying it to your iPad or iPhone. Here's a step-by-step guide explaining how to download YouTube videos to your computer.
See also: Is it legal to download YouTube videos?
Here's the original How To:
It's easy to download videos from YouTube so you can watch them on your iPhone or iPad later without a Wi-Fi or 3G connection. Here we'll show you how to save videos so you can watch them at any time, even when there's no internet connection.
Bear in mind that there are many apps which can download online videos, and they all work in the same way as we'll describe here. You don't have to use the app we're using, and you can have more than one installed on your device at the same time.
These apps are basically web browsers with the ability to save videos from certain websites - not just YouTube - but they cannot save those files so you can watch them in the native iPhone or iPad Videos app. Nor can they save only the audio from a music video to your Music library on your device. Apple doesn't allow this.
Having used such apps for years, we know that they often disappear from the app store, so search for 'video downloader' or 'YouTube downloader' and you will see a list of what's currently available.
Another issue with these apps is that - for no apparent reason - there's no pop-up 'Download' windows, or no save icon. There's no easy answer to why this happens, but the best way around it is to try another app. We've even used the same app on different iPhones and were able to download a certain video on one of them but not on the other.
One other thing to watch is that some free apps limit how many videos you can download before you have to upgrade to the 'pro' version. That doesn't happen with the free Video Downloader app we're using here, which is by Devstar apps. (You can click the images below to see larger versions.)
How to download YouTube videos to an iPhone or iPad
Step 1. On your device, go to the App Store and search for "Video downloader - download manager". Make sure to include the '-' so the app appears first in the list of results.
Step 2. The app is free, so tap 'Free' and then your password when prompted. There is a paid-for Pro version of the app, and you will see nag screens and / or adverts. If you don't like them, pay up.
Step 3. Launch the app (it's the one circled on the home screen below) and the built-in browser will open - it should default to Google.co.uk.
Tap the magnifying glass (circled, middle) and search for YouTube. Alternatively, tap in the address bar at the top, where it says google.co.uk and type m.youtube.com.
Step 4. Assuming you searched, tap on YouTube in the list of results and wait for the mobile site to load (it will default to the mobile version even on the iPad).
Now, tap the magnifying glass (circled, middle, below) and enter your search term. (We highly recommend watching the entire Project Binky series, by the way.)
Step 5. Pick a video from the list of results and it will start to buffer. If it doesn't automatically play, tap the play button (circled, below-left) and you should see a little disk icon bobbing up and down (circled, middle).
You should see a pop-up with the option to Download the video, as below, right.
Step 6. The video will continue to play, but you should see a little red circle with 1 inside it as a 'badge' over the Downloads link at the bottom. If you can't see it, tap on the video to bring up the interface, then tap Done.
You can tap on Downloads to see the current download progress (shown below, left), and once complete, you'll find the file in the Files section, circled below right.
Step 7. To play a saved video, simply tap on the Files icon at the bottom and tap the one you want - it will start playing. Simply rotate your device to landscape to watch it full screen.