I was wondering why basically all webpages use separate login and signup pages. Not necessarily separate html files, but they are usually built as two separate forms.

Why not have one form with email and password fields and two separate buttons, one for logging in and one for creating a new account? The only two arguments I could think of against this are

  1. People are used to separate pages.
  2. You might need additional data for signups.

The first one isn't really a strong argument because if the page is built right people will notice the difference right away. The second one also doesn't count for much in my opinion, because a lot of pages actually only need the email address, and also a lot of pages ask for additional information on a separate page later on anyways.

Do I miss anything?

  • That's a good question. I think part of this has to do with how users feel about intent. By keeping login / sign up as separate forms, the user's intent is defined before they enter any information. I don't know.. just a thought. Apr 21, 2017 at 13:33
  • Found this, to help the discussion: quora.com/… Apr 21, 2017 at 13:43
  • I think this is similar: ux.stackexchange.com/questions/82118/…
    – UXerUIer
    Apr 21, 2017 at 14:05
  • I think you'd be hard pressed to find a website that does not have a "confirm password" button on sign up (whether it should is a different matter), but that is a field you would not want on login. I think that reason alone is probably a big part of it.
    – DasBeasto
    Nov 21, 2017 at 18:05
  • 1
    this is a great question. as a user i hate both flows, because sometimes i try to log in through a sign-up flow only to see "you already have an account, click here" and i think - why can't you just sign me in i just gave you my credentials Jul 14, 2020 at 8:55

5 Answers 5


Because you want to keep it as simple as possible

Great question! I've had a chance to actually test it with one of my projects. We had a single form which required email and password, and we wanted to make it as easy for our users as possible to sign up. So if you wanted to sign in you just entered your email and password and you were in. On the other hand if you wanted to sign up, you did the same and we created the account for you.

enter image description here

The problem was communicating how this works to our users. Users are used to scan the screen looking for words or visual clues to guide them. So if they scan your sign in/sign up form, without a clear CTA saying Sign In, or Sign Up. They have to think for a moment, and that's where you usually loose them. So differentiating these two will lead to more clicks, but your users won't have to think about it.

But if you would still like to keep it in one form, there is approach. We're currently testing it so I will report later how it went.

enter image description here

  • 4
    I suspect one problem with the first version is: how would you distinguish between an incorrectly entered email/password (of an existing user) and a new user? You could assume that if one field is correct, it's a failed login attempt (but that could be used to harvest potential users), but if there's a typo in both, you'd be in danger of creating duplicate users. In the second version you have the user's intent (while avoiding the "two primary buttons" that DPS's answer mentions) so will know whether to show a failure or create the new account.
    – TripeHound
    Apr 21, 2017 at 14:59
  • @TripeHound It was an experiment that didn't go well. We required you to confirm your email address in 24h, otherwise your account would disappear so we didn't have a database full of duplicate accounts. This whole process was unnecessary complicated, so we've reverted back to standard Sign Up/ Sign In forms.
    – rojcyk
    Apr 22, 2017 at 8:46
  • @rojcyk how did the a/b test go?
    – demiculus
    Feb 21, 2023 at 15:59

An answer to this question might begin with a counter question:

Can we have two Primary Buttons for a same form?

As @rojcyk mentioned, it helps in completing the action quickly without cognitive load. On login page, we enter email & password then hit Enter. The same happens when we are signing-up, we enter necessary details and hit Enter.

If we maintain single form for both, we will force users to use mouse and select the appropriate action which the users may not like.

Another factor could be of Psychology.

The existing users are kinda family members who have a key to open the main door.

New users (strangers) need to provide more details to the house owner to gain trust and allow entry.


For me as a user...I go for speed and routine. Its moving the decision making up front instead of at the end. By selecting login up front...I can now do the rest very quickly without thinking. I typically enter in my info and by instinct hit ENTER without even looking at what the buttons say. If i did this on a pages with both options then I would get an error or redirected or something, which would be points against ux. Another scenario, if I did hit a button (again with little thought) and got an error message, then I would stop, look more closely and see the 2 options and wonder "which button did i hit? Did I even hit a button or press enter??" ...then start over. You see where I am going with this. They fewer chances for doing something wrong...the better!

  • This is a little anecdotal--can you provide some more evidence/sources to back your claim? Nov 21, 2017 at 23:29

It's an important question I can't find any good answers for.

One thing to consider is, people tend to forget which email they used while signing up and may end up multiplying accounts and getting confused about where their stuff is gone.

Second important thing is, a login system that tells you whether an account with given credentials exist or not is a potential security/privacy issue: someone might try someone else's email to see whether they use a given service or not. This is tough one to deal with.

In any case, the intention to create a new account vs. reuse an existing one should be made clear at the start.

I'm currently experimenting with a two-step process where the email is asked first, then depending on whether it's recognized by the system or not, the next step is worded differently ("Create an account" vs. "Sign in") with some visual/color distinction too. This doesn't solve the email probe/privacy issue above, but in my case it's not critical.


There are good answers here that explain in detail. However, I compile a list of issues you may face + things you need to think about:

  • Possible danger of creating duplicate accounts
  • Confusion between mistyping email/username & creating a new one
  • How will the Autocomplete be handled?
  • Increase of Cognitive Load: Users need to select whether they're signing up or logging in every time
  • Sign up page is used once; Login page is used many times
  • What if you want to add more fields in the signup form? (For example, asking user's age or a checkbox to "agree terms and conditions")

Feel free to add more items to the list, either by commenting and asking me to edit it or doing it by your own!

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