can these cards be used online?

[cardmakercauseicantusedecks]

i dont have the online but just wondering

[Flash Flyer - Sakura]

i dont have the online but just wondering

 

Assuming you are talking about custom cards (which likely is case).

 

If you go on Duel Portal, then yes, you can use stuff that you have made against other people.

 

There is also a separate server on YGOPro that permits the use of customs being used, however those get vetted first on their Discord (and I cannot say what their general standards are) before they actually get added. 

 

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Short answer is yes, but latter option gets vetted first and former, well, your stuff may be changed/removed from DP if members think it's too busted (but you should be told why before this happens).