Y Combinator Startup School

Y Combinator Startup School is a free online course on how to start a startup, run by Y Combinator, the world's best-known startup accelerator behind companies like Airbnb, Stripe and Coinbase. It's for anyone at the very beginning, turning a side project into a company, or just curious about becoming a founder. The content is taught directly by YC partners and experienced founders, so you learn from people who have actually built and funded startups.

It works as a self-paced curriculum you go through on your own schedule, typically over a few weeks at a couple of hours per week. The input is your ideas and questions, and the output is concrete advice on your MVP, funding, user acquisition and leading a team. A key element is the weekly update system, where you log your progress and metrics, so you measure real movement instead of just feeling busy.