Looking on the internet deeply has found these results:

log into facebook is the most popular phrase on the web.

log onto facebook 174,100 results on the web	log into facebook 114,600,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
I uploaded a lot of them onto Facebook. I'm trying to hack my reader, so I can get onto Facebook. Apparently Briony didn't even log onto their system. Stops first at the U and logs onto the computer. In fact, if you log onto the site, they should have posted pictures from last night's feast. Yes, I need you to help me get onto Facebook. We have learned to diary our pain onto Facebook, and we speak swiftly in 140 characters or less. Logged onto Facebook lately, Doc?	So the teacher can't log into Facebook until she gets home. Well, let me log into my Facebook. So I just went into Facebook. I'm downloading the logs into the Engineering computer core. The teacher can't log into Facebook, because the school has blocked access to Facebook. Whether Empathy should automatically log into your accounts on startup. There was a problem logging into Facebook. Check your credentials and try again. Next, we look into Facebook.

log onto facebook

174,100 results on the web

log into facebook

114,600,000 results on the web

More popular!

I uploaded a lot of them onto Facebook.
I'm trying to hack my reader, so I can get onto Facebook.
Apparently Briony didn't even log onto their system.
Stops first at the U and logs onto the computer.
In fact, if you log onto the site, they should have posted pictures from last night's feast.
Yes, I need you to help me get onto Facebook.
We have learned to diary our pain onto Facebook, and we speak swiftly in 140 characters or less.
Logged onto Facebook lately, Doc?

So the teacher can't log into Facebook until she gets home.
Well, let me log into my Facebook.
So I just went into Facebook.
I'm downloading the logs into the Engineering computer core.
The teacher can't log into Facebook, because the school has blocked access to Facebook.
Whether Empathy should automatically log into your accounts on startup.
There was a problem logging into Facebook. Check your credentials and try again.
Next, we look into Facebook.