To open Gmail, you can sign in from a computer or add your account to the Gmail app on your phone or tablet. Once you're signed in, open your inbox to check your mail. Sign in to Gmail Tip: If you sign in to a public computer, make sure to sign out before you leave the computer. Learn how to sign in on a device that's not yours. If you forget your Gmail username or password, or you canât access your account, follow our guide to troubleshoot your issue. If you still canât sign in, recover your Gmail account.