Yesterday, I signed up for Covoiturage.fr, a carpool website. I had to provide my name, email, phone number, but no password, which was weird. After completeting the quick process, I was sent a verification email which also included an auto-generated password. I didn’t use it because clicking the “Validate your email” button automatically logged me in for that one time, and I was able to send a private message like I wished to.

A few hours later, I got a notification email telling me I had received a message. I clicked on “View the message” and was sent to the website, which prompted me to login, considering my temporary session had expired. I tried using a usual password but it obviously failed, since I hadn’t provided one and had forgotten about the auto-generated one.

Almost instantly, I received this email:

Carpool access token

It gave me the ability to instantly connect to the website by using this single-use access token. I was both pleased and surprised to receive such an email: I just wanted to see the reply to my private message and didn’t want to bother finding and copy-pasting the auto-generated password, logging in to the website, and changing my password to an easier one.

There are some issues with the whole process:

  • I couldn’t define my own password at sign up
  • I was sent a login token after my first failed login attempt
  • It can encourage using this login method rather than the usual one

But despite these 3 small quirks, the login token made sense in this situation:

  • A carpool website is not a site you daily visit, but rather use on a punctual basis. So you’ll probably end up forgetting your password anyway.
  • Time is important: there are a limited number of seats and you need to react quickly. The login token made me gain valuable time.
  • Carpool users are probably mainly non tech-saavy, and are thus not good at managing passwords and/or coming up with a strong one. A login token might add a layer of security.

I ended up providing my own password but I understand why this login feature was implemented in the first place. If you’re developing a web app, you should consider providing an email access token after several failed login attempts. But, like anything, it should make sense in your context and shouldn’ be implemented in every case.