Checking if Winner Redeems a Game Won

https://www.sgtools.info/activation
Enter their username into the tool, and it checks for unactivated wins/multiple wins.
This may not work with dlcs though or certain games but they are listed in the tool.

Alternatively, you can visit their steam profile, and search their list of games manually to see if they have the game on their account.
(might be laggy if they have many games)

since there's "Steam is still learning about this game" thing there's no way to quick check if someone has redeemed a just released game.

So if u use "Your account must have activated all the won gifts" rule - some ppl with all wins activated can't enter your giveway

This is what I use...

Add links to SGtools
Add sgtools.info links to your giveaway's Winners page

If they don't have public profile, you can't check it on your own, you have to ask for reroll when they win your giveaway and Support will check it.

Otherwise, SGTools

I use this: http://www.sgtools.info/activation

And SilentGuy his SGTools links to SG profile script.

Btw when your winner has a private Steam profile you can ask SG support to check them with a request other winner ticket. When the ticket is denied the winner is OK. When the ticket is approved then you get a new winner.

sgtools is useless for any games with the steam is learning tag. They will show as a false positive. You have to check those manually.

View attached image.

Next time, when checking huge libraries, use steamdb calculator; you have link by default on steam profile page if you're using enhanced steam; I use it for checking if the winner already have game that he won. That is the fastest way for that.

Thank you to all of you that took the time to help me out. It truly is appreciated.