When you type your password on a website, all you see are asterisk (*) signs. That is probably a security measure in web browser to prevent people, sitting next to you, from finding your password.
A simple solution to prevent password typo errors is the show my password bookmarklet – just drag the link into your browser bookmarks.
Now the next time when you login into some website, just type the password and click the “show my password” bookmarklet before hitting the Submit button – this will reveal the actual password characters, not the asterisk signs. (see screenshot)