Lichess

Lichess, the free, ad-free chess server. Every line of code is public.

Why it matters

Free chess for everyone, with no ads and open code. Great for learning strategy.

Pro tips

1. Control the center (e4, d4), develop minor pieces before the queen and castle early.
2. Before each move, check which of your pieces hang and what your opponent threatens.
3. Solve puzzles daily to train tactical vision.
4. Use computer analysis after each game to find your mistakes.
5. Beginners should try 10+0 or 15+10 time controls to have time to think.

Image from the project's own page, README or Wikimedia Commons, owned by its creators. Source