Why Yahoo Mail Doesn't Keep You Logged In

A security feature may be to blame

Yahoo! homepage with Mail on Windows Desktop

Even though Stay signed in is checked on the Yahoo Mail login screen default, Yahoo still might prompt you to log in each time you visit mail.yahoo.com. The issue is login cookies, which are bits of data that help identify you and tell Yahoo that you've been there before.

Login Cookies Are Browser- and Device-Specific

The cookie your browser saves when you visit Yahoo Mail applies only to the browser and device you were using at the time of your visit. As long as you visit the login page with the same device and browser, you won't have to log back in.

However, if you attempt to log in with a different device or browser, Yahoo won't find the login cookie, so you'll have to enter your username and password.

If you are using the same device and browser but are still prompted to log in, then something or someone deleted the cookie in your browser that would log you in automatically.

How to Keep the Yahoo Mail Login Cookie

You can prevent your computer from deleting your browser cookies, including the one for your Yahoo Mail login credentials, in a few ways:

Stay Signed in checkbox checked on Yahoo Mail website

When you log in to Yahoo Mail, confirm that the box next to Stay signed in under your login credentials is checked.

Sign out button greyed out on Yahoo Mail website

Don't click Sign out in the box that appears when you click your name at the top of any Yahoo page.

Clear data button in Chrome

Check your browser's settings to make sure you haven't set it to delete cookies when you close it.

Set browser extensions and anti-spyware software not to clear cookies and not to exclude cookies from the yahoo.com domain.

About Private Browsing

For enhanced internet privacy, you can use your browser's private browsing feature to visit websites without storing cookies on your computer. That way, you won't feel the need to delete them as often, but you'll have to sign in to Yahoo Mail each time you visit. Using this feature frequently may explain why your login information isn't saved.

The various browsers have different names for the private browsing feature:

If you'd like not to log in to Yahoo Mail each time you visit, don't use private browsing.