Login to YouTube on the iPhone with Google Accounts
If you can't login to YouTube on the iPhone, there are simple steps you can take to allow the native YouTube app on your device to connect. The problem arises when your linked Google Account does not have an application-specific password set up for your iPhone YouTube app.

After repeatedly trying to login to your YouTube account with the correct username and password, the iPhone prompts you to login from Safari. Even after following through this process, the YouTube app refuses to acknowledge your credentials are correct. The iPhone error states wrong username or password.
To correct the problem, you must first activate 2-step verification on your Google Account. After this is complete, you can create an application-specific password for the iPhone. After failing to login to your YouTube account from the iPhone app, open a web browser on your computer.
Navigate to Google.com and click the Sign In button to open your Google Account. Once you are logged in, click your email address and choose Account from the drop down menu. Click Security -> Authorizing applications and sites -> Edit. You may see a screen like the following:

The application-specific password section is greyed out because you don't have 2-step verification set up on your Google Account yet. To make this happen, click your email address in the top bar and select Account. Now navigate to Security -> 2-step verification -> Edit.

After clicking the Edit button, follow the steps to enter a phone number for 2-step verification. Once complete, Google will send a text message or voice mail to your phone with a verification code. Enter this into the box and this will confirm you have set up 2-step verification. A pop-up box like the following may appear:

Click the Create passwords button. If this dialog box does not appear, navigate to your email address again and click Account. Choose Security -> Authorizing applications and sites -> Edit. If prompted re-enter your Google password. You now have the option to generate a new application-specific password. Name your password something you will remember such as "YouTube" and click Generate password.

Google will generate your application-specific password and display it once. Do not close this window until you have followed the next step.

On your iPhone, open the YouTube application. On the bottom menu touch More -> Sign In. Enter your Google Account email address (NOT your YouTube username), followed by the application-specific password in the yellow box on your computer web browser.
You should now be logged into your YouTube account on the iPhone. If you ever need to generate a new application-specific password, you can accomplish this using your Google Account on the computer.
I've followed these instructions to the letter, but after entering the password into Youtube, it STILL says 'Authentication Failed. The username or password you entered is incorrect." Please help!
I still doesn't work! :-( I get the same message. Help!
Yup, me too. All goes smoothly until I signed in to YouTube and it is still Authentication Failed.
Just helped my mom out with this...she set up the 2 step verification and app specific pass word and it didnt work heres how we fixed it
Follow these instructions above but you also have to log into youtube, click the upload video button and it wil give you the option to create user name......Create a new user name, then use this new username and app specific password to sign in
GOod luck this should work
Thank you so much! It worked!!!!
it wont work for me i made a 2 step verification i changed the name of the account but it still says authentication failed
Have you tried entering the password with spaces. That worked for me.
Doesn't work at all. Thank you Google for overcomplicating things and in the process completely making the YouTube app unusable. You should all be fired.
apple need to sue those google fags!!! this is outrageous!!
Followed this to the letter and i am still unable to sign into the youtube account that was working just fine this time yesterday... So this information is out of date
I HATE THIS
why won't it work
wow... completely useless!
no thanks
J
cant find the security button on my google account
same for me, ive been pissing about all day on this trying everything and nothing working. Anyone with a solution after trying a rename username....I dont even get the create username option when clicking upload video button going through my computer...help help help.
It worked for me, but there is a typo in the article. It says to name your password something easy like "YouTube." He meant name the application YouTube. Then, when I logged into the YouTube app on the iPhone (by pretending I wanted to upload a video from my Camera Roll to YouTube), I used just the main part of my Google email without the @gmail.com as the username login.
FYI, at the start, I didn't follow his instructions to repeatedly login to the YouTube App until It prompts you to use Safari. I had gotten the incorrect username or password error a couple of times before I tried what this article said to do.
However, I need to do more investigation, but I just realized that my email on my iPad is now telling me my password for my Gmail account is incorrect. So, I don't know if this is a coincidence or due to the changes I made to my iPhone.
Update...yes, the two step verification broke my email on everything I had (iPhone, iPad and MacBook), so I decided that the convenience of having email on these devices was more important than being able to upload to YouTube. I could have set up a two-step for email too, but why bother...
Nothing works! legacy account doesn't work either. At this point I don't even care about all my old stuff, I just want to start over. But I can't just create a new youtube account cause it is linked to you google account. Great Work!