UX case study for log in and sign up buttons

If you're like me, then you've tried to log into a website and got confused with which button to click. The placement, terminology and styling often throws me off. For authentication we often see log in, sign in and for registration words like sign up or create account.

In this case study, I want to determine which terminology should be used as default for authentication and registration buttons. Then, identity common patterns of placement for these buttons when viewed on a personal computer (monitor) not a mobile device. We will look at 10 common social media websites and 10 web developer websites and see what they do.

Social Media Sites

Url	Auth	Registration	Placement
facebook.com	Log In	Create New Account	Landing page right
twitter.com	Sign In	Sign Up With ...	Landing page right
linkedin.com	Sign in	Join Now	Landing page left; Nav top right
youtube.com	SIGN IN	Create Account	Nav top right; Registration is hidden behind Auth form
pinterest.com	Log in	Sign up	Nav top right
instagram.com	Log In	Sign up	Landing page right
tumblr.com	Log in / Log In	Sign up	Landing page center; Nav top right
twitch.tv	Log In	Sign Up	Nav top right
flickr.com	Log In	Sign Up / Start for free	Nav top right
reddit.com	Log In	Sign Up	Nav top right

Developer Sites

Url	Auth	Registration	Placement
github.com	Sign in	Sign up	Nav top right
about.gitlab.com	Login	Get free trial	Nav top right
developers.google.com	Sign in	n/a	Nav top right
aws.amazon.com	My Account	Create an AWS Account	Nav top right
azure.microsoft.com	Sign in	Free account / Try Azure for free	Nav top right
cloudflare.com	Log In	Sign Up	Nav top right
digitalocean.com	Log In	Sign Up	Nav top right
godaddy.com	Sign In	n/a	Nav top right
npmjs.com	Sign In	Sign Up	Nav top right
codepen.io	Log In	Sign Up	Nav top right

Conclusion

Authentication

Log in or variations - 11
Sign in or variations - 8

Registration

Sign up or variation - 12
Create ... or similar - 3
remaining terms are all unique

It appears that the results for authentication lean slightly towards the wording Log in while Sign in is a very close second option. For registration, Sign up is the clear winner. Other options vary, but Create ... seems to be the next most viable.

If Sign up is chosen for registration, then it would be logical to avoid Sign in because they are so similar. Although styling the buttons differently may help distinguish Sign in & Sign up, they only differ by one letter so it is easy to mistake.

As for registration, most occurences of Create ... happen when the action is displayed in the Landing page, not the nav. Since the nav often contains many items, using Create ... may take up too much horizontal space. Having succinct terms for the nav would reduce visual clutter.

Rules

use Sign Up for registration by default.
use Log In for authentication by default.
accent the registration button Sign Up with a border or background color.
position Log In and Sign Up buttons on the top right of the page. Preferably on the top nav bar.
position Log In before Sign Up.
using Create Account or a variation is permitted for registration if there is enough horizontal space. Preferably on a landing page form.
using Sign In is only permitted for authentication if Sign Up is not used for registration.