‘Login’ or ‘log in’? One word or two? It’s an oft-debated question. I’m not proposing a hard-and-fast rule, though I do have my preferences. What this post offers is a handy way of choosing between one word and two, if it’s important to you.
It’s not just logging in that’s affected. There are plenty more cases where we need to choose one word or two:
‘logon’ or ‘log on’
‘logout’ or ‘log out’
‘signup’ or ‘sign up’
‘shutdown’ or ‘shut down’
‘backup’ or ‘back up’
‘setup’ or ‘set up’
and more, including words not related to computing, such as ‘workout’ versus ‘work out’
Who’s up for an experiment?
Warning: Don’t try this at home, unless your partner is in a good mood.
Try speaking these sentences out loud, replacing ‘bbbbbbb’ with ‘backup’ and ignoring the spelling for now:
What is your bbbbbbb strategy?
When did you last bbbbbbb your data?
When did you last do a bbbbbbb?
Now try these, replacing ‘llllllll’ with ‘login’:
What are your llllllll details?
Where can I llllllll to the bank’s website?
My llllllll failed.
Did you notice any pattern in the way you pronounced the words “back/up” and “log/in”? If you’re like me, your stress pattern in the middle sentences would be different from the first and third sentences.
In the middle sentence, you would give equal emphasis to both parts of the phrase: back up; log in.
In the first and third sentences, you would give greater emphasis to the first part of the phrase: backup; login.
And the answer is…
‘Backup’ or ‘back up’:
What is your backup strategy?
When did you last back up your data?
When did you last do a backup?
‘Login’ or ‘log in’:
What are your login details?
Where can I log in to the bank’s website?
My login failed.
Rules and things
It may be that you decide to go with the growing common usage, and just use one word (like ‘login’) for everything. But if you want to follow the ‘rules’, they’re something like this:
If it’s a verb, use two words.
If it’s a noun, including cases when the noun is used to qualify another noun, use one word.
What about hyphens (‘-’)? Technical writers try to avoid them.
Who decreed that this is how it’s done, and where is it written down? Most tech writers and other guardians of language would agree that we should be descriptive rather than prescriptive, and that there are a equally-viable alternatives out there. But we also agree that it’s good to have a standard, so that our readers have a smooth ride through the documentation and application screens.
Here are some style guides and commentaries that agree we use one word for a noun, two for a verb:
Guardian and Observer Style Guide – Scroll down to the entries for ‘log in’ and ‘login’.
Apple Style Guide – See the entry for ’log in (v.), login (n., adj.), log out (v.), logout (n., adj.)‘, on page 96.
Log in vs. login by Grammarist – This post has some useful examples from online newspapers.
A thread on the English Language and Usage Stack Exchange – People express various opinions, but the consensus is one word for a noun, two for a verb.
Another thread on the English Language and Usage Stack Exchange – This one is particularly cool, because someone pointed out in a comment that the instructions on the Stack Exchange page itself said ’Sign up or login’, and Stack Exchange fixed it!
The Wikipedia page on login – The page consistently uses ‘login’ as a noun and ‘log in’ as a verb. It also states, ‘The noun login comes from the verb (to) log in‘.
And someone who has a strong opinion, backed up by good research: “Login” is not a verb.
Who cares? Is this a difference between US and British usage? I don’t think so. It’s more a difference between people who feel a sense of jarring disconnect when someone uses ‘login’ and the like as a verb, and people who don’t. If you do want to differentiate, the pronunciation test may be the quickest way to decide whether you need one word or two.
There’s only one word for this spider: Eek!
This spider took up residence between my window panels for a while. It’s a huntsman: huge, very fast, scary but beautiful, and largely harmless. I put the peg there for scale. It’s a large peg.