Why is Chrome calling the autocompleted url before validation?

Question

I'm using an API on my website to send emails to the users and while testing my call I noticed I was receiving the email twice.

So the url looks like "localhost/api/sendEmail" and, at least on Chrome, when I'm on localhost and I start typing "/ap" the url is automatically completed.

And I can see on Fiddler that Chrome (well I think that's him) is actually calling it before I press Enter so the mail is sent, and when I press Enter it is of course sent a second time.

This is not a problem since it won't be directly callable by the end-user, but I was just wondering what is the purpose of this first call ? Is Chrome pre-calling the page to make it faster to load ? Can it cause problems in different situations? Can one prevent Chrome from behaving like this?

Again, not a problem at all, but I'm just wondering.

Answer 1

This is Google's prefetch feature, which loads the page quicker, assuming you execute the auto-completed URL.

You can disable this option in Google Chrome:

Settings > Advanced Settings > Privacy: (uncheck) Prefetch resources..