Sexing Pacman Frogs

[Sykomaus]

What is the most reliable way to sex a Pacman frog? I've heard that if it croaks, it's male, and if it doesn't, then it's female. Mine is only young so I figure if it IS male, it won't croak for a while yet. But I was wondering if there are any visual aspects which indicate M or F?

Thanks.

[MatthewM1]

Beside the croaking, males develops nuptial pads of the side of their "thumbs", but you won't see this untill it gets larger as well.

[Sykomaus]

I didn't know that, thanks!