If you only have one password to try, I'd say you have more important issues to tackle. Install a password manager, start using generated passwords, and stop using 'your password'.
"Pick a password length. Eight is pretty secure and usually acceptable." Wait, what? Unless you're suggesting that I append this to a password.
you can choose any area of the card, say 5 letters and a few keywords.
Well, in that case, it should already be something that's staggeringly improbable to be used by anyone else, and for your use, you should never ever ever send this password through any network interface at all (including this check page).