Is there a website like sims online or imvu on second life or vavity but for free with no downloads

Yes, there is:


Gaia Online


Habbo


Stardoll


I- Dress Up


Gosupermodel


Vizwoz


Zwinky Cuties


Meez


BoomBang


active worlds


dizzywood


Panfu


Pandanda


binweevils


clubpenguin


World Village


Roblox


Kidscom


I hope this helps and anyway for Sims you have to download it.