The Best Free Online Sudoku Games in 2026
Six free online Sudoku sites and apps worth your time in 2026 — with honest notes on ads, signup walls, and difficulty selection.
Free online Sudoku is a crowded space. Most sites are covered in ads or push a signup after two puzzles. Here are six that don't — ranked for how respectful they are of your attention.
1. Puzzle Theory Sudoku — daily, no signup
Sudoku on Puzzle Theory serves one shared daily puzzle across four difficulties, plus practice. No account, no popups, keyboard-first.
2. Sudoku.com — massive library, mixed UI
A huge selection of daily and archive puzzles. Interface is dated, but the puzzle quality is solid.
3. NYT Sudoku — three daily puzzles
Easy, medium, hard, dropped every day. Requires an NYT account after a few plays.
4. Sudoku Wiki — the technique lab
Best if you're learning solving techniques. The interface is spartan but the pedagogy is excellent.
5. Cracking the Cryptic (YouTube + app)
Not a Sudoku site so much as a Sudoku universe. Home of variant Sudokus (killer, thermo, arrow).
6. Web Sudoku — the classic archive
The one every Sudoku fan bookmarked in 2008. Still works, still ad-supported.
Where to start
If you want a calm five-minute daily habit, play today's Puzzle Theory Sudoku. For solving technique, read our Sudoku strategy guide or Sudoku solving techniques for beginners.
Frequently asked questions
What's the best free online Sudoku site?
For a daily-puzzle format with no signup, Puzzle Theory. For a massive archive, sudoku.com. For learning technique, sudokuwiki.org.
Are there free Sudoku sites with no signup?
Yes — Puzzle Theory, Web Sudoku and sudokuwiki.org all work with no account. Puzzle Theory also has no popup ads.
How many difficulty levels does daily online Sudoku usually have?
Most quality sites offer three to four (easy, medium, hard, expert). Puzzle Theory serves all four difficulties every day.
Can I play Sudoku on my phone without an app?
Yes. All sites in this list work in a mobile browser with tap-to-fill input.
How long should a daily Sudoku take?
Easy: 3–6 minutes. Medium: 6–12. Hard: 12–25. Expert: 20–45. Faster comes with technique, not effort.
Play a puzzle
Put the ideas from this article into practice with today's daily challenge — or browse all our games.