"log in to" or "log into" or "login to"

When writing an instruction about connecting to a computer using ssh, telnet, etc., I'm not sure what spacing to use in this familiar spoken phrase:

• "Log in to host.com"
• "Log into host.com"
• "Login to host.com"

Maybe this is entirely subjective or the realm of industry jargon, but I couldn't think of anywhere else to ask. Any insight?

Solution 1:

I would write “Log in to host.com.”

I think that “login” is a noun (as in “login screen”). I would find the words “loginned” and “loginning” awkward.

As for “Log in to host.com” versus “Log into host.com,” I would use the former because I think that “log in” is a fixed phrase. Martha’s answer to another question is also related.

Added: The Corpus of Contemporary American English (COCA) lists 65 occurrences of “log in to” and 58 occurrences of “log into,” both including inflected forms and excluding the Spoken section. (The queries used are [log].[v*] in to and [log].[v*] into.) Since “log in to” is also used in context like “log in to download it,” the actual number of occurrences of “log in to [host]” is slightly smaller than 65. In any case, it suggests that the phrase “log into” is also used commonly, although I am not sure how good it is to use COCA to compare technical terms.

Solution 2:

The verb is log in.

Log in to host.com

From the Wikipedia page for Login:

Spelling confusion

The verbs are two words: log in and log out, whereas the nouns are login and logout (often used like adjectives in compound nouns).

Solution 3:

• Yes, I agree: Use "log in to" as a verb. So use that for giving instructions.
• "log into" is not terrible, but it doesn't sound as good because it sounds like you're actually going inside something. For example, "I walked into the store."
• "login" is the noun and adjective form. So you would use that like this: "I programmed the login procedure." Or... "I don't like this app because the login process is very lengthy."

You can also think about each one with the way we stress the different syllables slightly when we're speaking:

• "log in to host.com" sounds like "log + in + to host.com" (each word is pretty much evenly stressed)
• "log into host.com" sounds like "log + INto host.com" (the stress is on "in")
• "login to host.com" sounds like "LOGin + to host.com" (the stress is on "log")

Solution 4:

Ironic that the instruction at the bottom of this page is 'Sign up or login'.

I'm here because I'm torn between log in to and log into and looking for clarification. At this point in time, I suspect the prevailing opinion is correct - that log in to is preferable for purposes of clarity.

However, I don't doubt that we will soon treat the process of logging in as a figurative point of entry, meaning that log into will make full conceptual sense (cf you don't physically delve into a problem or pile into an argument, yet both are correct grammatically because they are semantically [i.e. figuratively]).