How do I use vanilla visa gift cards for steam funds

[salguod]

Title says it all :-)

[Ogami]

Use the option to charge your Steam Wallet:
https://store.steampowered.com/steamaccount/addfunds

And then just use the prepaid VISA card as payment method.
I dont think you can use it as a regular credit card to buy games directly since for first time use Steam would need to send some small money value to the card to verify it and that does not work with VISA gift cards.

[Fake]

Take the visa gift card to a store and buy a Steam card.