Use user, email or one of the two for authentication?

Question

I am developing an application that, like all others, will need the user’s email for some purposes. Each user will also have a unique username for their profile page:

/u/:username

The question is: during the authentication process (alias login), should use the username, e-mail or one of the two (e-mail or user)?

I ask this because for my application, it doesn’t matter. But I’m left in doubt taking into account that this can have a slight impact on the user experience (especially of older people, I think).

When looking at some sites, I see that most of them ask for one of the two, but I would still like an answer. :)

Answer 1

For a better user experience, it would be interesting for the person to access the system with both. Email and user! I’m just saying that for accessibility. When working only with user and password, without email, can hinder access, especially when the person does not access the system for some time. Already with e-mail this can decrease, because it is much simpler for most of the time we always use the same email. In addition, you give more options for the user to access the system. There is something plastered. Another point too, is when the experience is by cell phone. For some people it may be interesting to access the system via user by having fewer characters than email. For some, email can be more useful because it is easier to remember. It is only important to put a placeholder or span warning that the user can log in in both ways.

I find it very interesting to work using email and the user. And to further improve accessibility, it would be cool other options such as login via facebook, google, github, etc... Having options available is always very good.

Answer 2

When talking about user experience you always have to consider who this user is. According to each type can be a different response. In general it is said that it is not possible to answer this without conducting an experiment and careful evaluation to decide what is most appropriate.

If you really want a generalized form that may not be the best for your typical and most important user, and you need a more appropriate experience, then I would say allowing the two forms looks better. Actually, I keep asking myself why I would do it differently. I see only advantages in this, except that someone can get in the way of having options, especially if the details of the implementation allow it.

But it’s not the end of the world today to have one just because you almost always access it using auto-fill and you don’t have to remember or have to put the data there. Of course, not everyone uses this facility. Don’t forget to have a secure way to regain access for one of these two. In some cases it may be interesting only to accept email in recovery to avoid disturbing users when someone tries to recover with a similar name user.

Again, what will give real good user experience is not this decision but all the details of how it will be done.

Some consideration that seems silly but I think important: "both" implies that the two will be used, is a And, And that doesn’t even think about it, but it was then put "one or the other" which is the opposite of both, so ok. Such care is important especially when speaking of UX. The other answer states that it should be "a and the other, "which I think was only in the way, why would I do this? It is a complication to require both for almost zero gain (it has a slight security advantage but almost irrelevant). It may be that it was only said by carelessness since then she says the opposite.

This has nothing to do with accessibility, it has only to do with usability, they are different concepts.