Puzzle Fuel publishes a numbered daily edition of five puzzle games — Sudoku, Killer Sudoku, a Mini Crossword, Word Ladder and Wordcraft — plus a free course that teaches sudoku properly.
Everyone gets the same puzzle
Today’s puzzle has a number on it, and everyone solving it is solving the same one. That’s the whole idea of a daily. It isn’t a random grid pulled off a pile the moment you land on the page — it’s an edition, and tomorrow there will be another.
The same numbered edition goes out everywhere Puzzle Fuel appears: on this site, on the library websites that carry our puzzles, and anywhere else we publish.
Every puzzle has an editor
Puzzles here are reviewed before they run. That means someone looks at the grid, the clues and the difficulty label, and throws out what isn’t good enough — a clue that’s doing two jobs at once, an answer that turned up too recently, a grid that’s technically valid but no fun to solve.
It is a small operation, so that editor is David Nelsen, the person who runs the site. Not a rotating pool of freelancers and not nobody at all, which is the more common arrangement.
Three things every sudoku has to be
A puzzle doesn’t reach the site unless all three are true:
- One solution.Not “probably one” — the solutions are counted, and a grid with two is thrown away.
- Solvable by logic alone.You should never have to guess a digit and backtrack to see whether it worked. If a grid can’t be finished by reasoning, it doesn’t run.
- Rotationally symmetric. The givens form a balanced pattern, the way a puzzle in a good newspaper does.
These are checked on every release, across every game and every difficulty. It’s not a spot check, and it isn’t optional.
Difficulty that means something
Most puzzle sites set difficulty by counting how many digits they took away. It’s a poor proxy — a 24-clue puzzle can be gentler than a 30-clue one, and anyone who solves regularly has felt it.
Ours are graded by the hardest move they actually require. An Easy puzzle gives way to singles. A Diabolical one will make you find an X-wing or spot a unique rectangle. Moving up a tier asks a genuinely different skill of you, rather than handing you the same puzzle with more holes in it.
We’d rather teach you than tell you
Most sites give you a hint button that fills in a square and explains nothing. Ours names the move.
When you’re stuck, Puzzle Fuel finds the next step that genuinely follows and tells you which technique it is and why it works — twenty of them, from naked singles up through X-wings, swordfish, Y-wings and unique rectangles. Each one has a full lesson with a worked board, and the sudoku course walks the whole ladder from the first move to the last.
A hint you don’t understand is just a spoiler. The point is that you leave better at this than you arrived.
Free for libraries and schools
Public libraries, schools and community organisations can put our daily puzzles on their own websites at no cost — no contract, no account, and no advertising inside the puzzle. Several already do. If you’d like the code, ask usand we’ll send it.
Who builds it
Puzzle Fuel is built and run by David Nelsen. It is small and independent — not a content farm, and not somebody else’s puzzle library with a new coat of paint. The puzzles, the lessons, the site and the tools behind them are all made here.
“I love to play Sudoku every day. Given my love for puzzles, I decided to build my own puzzles and here we are today with Puzzle Fuel. I hope you all enjoy the website, send me feedback anytime!”
Questions, broken puzzles, embedding requests and press enquiries all go to the same place: the contact page. A person reads them, and you’ll get a reply.
What we won’t do
You can play every puzzle without an account, without handing over an email address, and without paying. There’s no premium tier holding a puzzle hostage, no countdown pushing you toward a subscription, and nothing to buy.
We don’t sell or rent your email address. If you make an account you can delete it yourself, and deletion means deletion. It’s all in the privacy policy, written in plain language rather than boilerplate.
Still being built
New games arrive when they’re ready rather than on a schedule, and the older ones keep getting better. If a puzzle here is wrong, unfair, or just not enjoyable, say so— that’s genuinely the most useful thing you can send us.