Sudoku Unlimited
Sudoku Unlimited is a free Sudoku with no daily limit. Puzzles come in five levels, each with exactly one solution, and your rating moves with the level you solve and how quickly and cleanly you solve it.
Loading a puzzle.
Level:
Rating
This page shows Google ads. They are how the unlimited puzzles stay free.
How it works
Fill the grid so every row, column and 3 by 3 box contains the digits 1 to 9 once. Click a square and type a digit, or use the number pad. Duplicates turn red as you go. When you finish, your rating moves and the next puzzle is one click away.
Levels and ratings
| Level | Rating | What it needs |
|---|---|---|
| Beginner | 900 | Only singles. |
| Easy | 1250 | Adds locked candidates. |
| Medium | 1600 | Adds pairs and triples. |
| Hard | 1950 | Adds X-Wing. |
| Expert | 2300 | Needs a forced guess to get started. |
Questions
What do Digit first and Zen do?
Digit first lets you pick a digit on the pad and then tap squares to fill them. Zen hides the clock, though the time is still used for your rating. Both settings are remembered on this device.
How does the rating work?
It is an Elo rating. Each level has a rating: Beginner 900, Easy 1250, Medium 1600, Hard 1950 and Expert 2300. Solving a level above your rating gains more. Solving faster than the level's usual pace earns a bigger gain, a slow solve earns a smaller one, and a solve with checks or reveals counts for less.
What are the five levels?
Beginner needs only singles. Easy adds locked candidates, Medium adds pairs and triples, Hard needs X-Wing patterns, and Expert needs a forced guess to get started. Every puzzle has exactly one solution.
Which level will I get?
The level follows your rating, with some variety. As your rating climbs you see harder levels more often.
What does New puzzle do?
It gives up the current grid and counts as a miss, so start one only when you mean to leave it.
Is there a daily limit?
No. Puzzles come from a large pool, and each one is relabelled and reshuffled so repeats look different.
Do I need an account?
No. Without one your rating is kept on this device. Signing in with an email link keeps it across devices and lets you join the leaderboard if you choose.
How do the leaderboards work?
Signed-in players can opt in under a display name. The board shows the top 100 by rating and the top 100 by rating gained this week. The rating service works out the rating itself and refuses reports that are for unknown puzzles or too fast to be real.
Are there ads?
Yes. This page shows Google ads, which is how the unlimited puzzles stay free. The daily games have none.
Tips for Sudoku Unlimited
- Scan for squares where only one digit fits before you start using notes.
- On Hard and Expert, look for pairs and triples of candidates in a row, column or box.
- Solving faster than the level's pace earns a larger gain; slow solves still count as solves.
- New puzzle on an unfinished grid counts as a miss, so finish or skip deliberately.
- Ratings settle after about 20 puzzles.