About Sudokuno
Sudoku should be challenging, logical and fun to solve.
Sudokuno is a free Sudoku game built with one simple ambition: to create a better Sudoku experience.
Here you will find everything from easy puzzles for beginners to advanced logical challenges, with a carefully designed interface, helpful hints and a Sudoku generator of its own.
You can play straight in your browser on phone, tablet and PC, with no download and no account needed.
The story behind Sudokuno
Sudokuno started as a hobby project early in 2026. I missed a Sudoku game that combined good, challenging puzzles with a user-friendly interface and hints that actually explained something. There were plenty of options, but none gave me quite the experience I wanted. So I decided to make my own.
After a couple of desktop versions, I started building the website in April 2026, partly so I could share the puzzles with my father, who is still an important test player. I develop Sudokuno in my spare time alongside my master's studies at NHH. The project has grown quite a bit since it started, but the starting point is the same: to make a Sudoku game I want to use myself.
What makes a Sudoku good?
A hard Sudoku is not necessarily a good Sudoku. A puzzle can be time-consuming because it hides one simple logical move at a time, but that does not make it an interesting challenge. I wanted a generator that considers more than just how hard a puzzle is to solve.
That is why Sudokuno has its own Sudoku generator, built to make puzzles that:
- Flow naturally from start to finish.
- Vary the logical techniques they use.
- Offer interesting challenges and logical breakthroughs.
- Have a difficulty that reflects the techniques they actually require.
It is not always easy to get all of this into the same puzzle, and the generator keeps improving. But these are the principles behind how the puzzles are made.
Difficulty based on logic
In Sudokuno, difficulty is not mainly about how long a puzzle takes to solve. It is built around which solving methods you need.
There are five main levels:
- Rookie: Basic techniques such as Naked Singles and Hidden Singles.
- Apprentice: Introduces techniques based on pairs.
- Enthusiast: Extends the challenge with techniques based on triples.
- Specialist: Requires more advanced techniques, such as X-Wing, Y-Wing and Unique Rectangles.
- Technician: For when you want a bigger challenge, with at least two advanced Specialist steps in the same puzzle.
The idea is that you can build your skills gradually and meet new challenges as you learn more techniques.
Hints that help you understand
The hint system in Sudokuno is built to explain the logic behind each step.
When you are stuck, it helps you see where to look, which candidates matter and which pattern to notice. That way you get the chance to understand the reasoning before the solution is finally revealed, if you want it.
The goal is that you learn something from the hint and perhaps manage the same technique on your own next time. Alongside the hints there is also a library of Sudoku techniques, with explanations and examples for anyone who wants to learn more.
An interface made for solving Sudoku
A good Sudoku game is not only about the puzzles. It is also about the tools you have. Sudokuno is designed around a clean, intuitive interface that lets you focus on the puzzle itself.
You can use colouring, among other things, and there are several ways to note candidates. That makes it easier to explore possibilities, keep track of your own reasoning and work through hard techniques. By choosing a game mode you can play by the classic rules, or try our Friendly or Forced variants for a different kind of Sudoku.
On a phone or tablet you play with the on-screen buttons. On a computer you can also use keyboard shortcuts, but they are optional.
Sudokuno also has its own mascots that give the game a little extra personality. They show up when you finish or end a puzzle, with different reactions depending on how it went.
Free Sudoku, your way
Sudokuno is free to use, and every difficulty level and every hint is available to everyone. The site is also ad-free today.
You do not need an account to play. If you want to keep your results, you can create a free account without giving an email address. You can then follow your best times across devices and compare results with other players.
Sudokuno will keep evolving, with new features, techniques and improvements along the way.
Have a suggestion, found a bug or want to give feedback? Send an email to contact@sudokuno.com.