There's Flippa <a href="https://www.flippa.com/" rel="nofollow">https://www.flippa.com/</a> and you'll find more with a bit of googling.<p>But those are platforms for selling "online business" not "side projects".<p>People who buy want ROI (Return On Investment). They buy money-making business for some multiple of monthly revenue hoping that over time they'll make more than they spent.<p>It might be just a careless use of terminology on your part.<p>Or it could be fundamental misunderstanding of how the world works.<p>No one buys "side projects". Don't try to sell "side projects" because you can't.<p>People buy businesses. A business makes money. There are people who will buy a money-making business.<p>Some side projects could also be money-making businesses but not all of them are.