Sudoku needs no introduction. The 9x9 grid with the simple rule — every row, column, and 3x3 box must contain the digits 1 through 9 — is the most popular logic puzzle in the world. But the digital sudoku landscape goes far beyond the classic grid.
This list covers the best sudoku apps, the most innovative number puzzles, and the games that have expanded what "number puzzle" means. Whether you want a clean daily sudoku or something that will keep you up until 2 AM, there's a game here for you.
1. Good Sudoku
Developer: Zach Gage (indie) | Released: 2020
Platforms: iOS, Android
Difficulty: Adaptive | Price: Free (limited); $3.99 for full version
The sudoku app that actually teaches you to think like a sudoku solver. Zach Gage (SpellTower, Typeshift) redesigned the sudoku experience from scratch, adding visual note-taking tools that highlight patterns, candidate eliminations, and logical chains. Good Sudoku doesn't just present a puzzle — it shows you the path to the solution.
The "hint" system doesn't just reveal a number. It highlights the logic technique you need to use, teaching you strategies like X-Wings, Swordfish, and hidden pairs as you play. It's the best sudoku app for players who want to get genuinely better, not just fill in numbers.
2. NYT Sudoku
Developer: The New York Times | Released: 2021 (added to NYT Games)
Platforms: Web, iOS, Android (NYT Games app)
Difficulty: Easy to hard (three daily puzzles) | Price: Free with NYT Games subscription
The NYT's entry into digital sudoku is clean, no-frills, and daily. Three difficulty levels each day — Easy, Medium, and Hard — with a timer and error checking. The NYT's editorial quality control means the puzzles are consistently well-constructed with elegant solution paths.
For players already in the NYT Games ecosystem (Wordle, Connections, Spelling Bee), sudoku fits naturally into the daily rotation. The lack of ads, power-ups, or in-app purchases is refreshing in a category saturated with them.
3. Cracking the Cryptic App
Developer: Cracking the Cryptic (Mark Goodliffe & Simon Anthony) | Released: 2021
Platforms: iOS, Android, PC (Steam)
Difficulty: Medium to extremely hard | Price: Free (limited); puzzle packs $2.99–$4.99
Born from the wildly popular YouTube channel where two British puzzle experts solve fiendishly difficult sudoku variants on camera, the Cracking the Cryptic app brings those same puzzles to your phone. Classic sudoku, Killer Sudoku, Sandwich Sudoku, Thermometer Sudoku, and dozens of other constraint-based variants.
The YouTube channel has over 1.5 million subscribers, and watching Mark and Simon solve puzzles has turned competitive sudoku into a spectator activity. The app gives you the puzzles they solve on screen — and you quickly realize how much harder they are than they look.
4. Sudoku.com
Developer: Easybrain | Released: 2017
Platforms: iOS, Android
Difficulty: Easy to expert | Price: Free (ads); premium subscription removes them
The most downloaded sudoku app globally, with over 100 million installs. Sudoku.com offers daily challenges, seasonal events, a statistics dashboard, and four difficulty levels. The pencil mark system, undo button, and hint system are polished and intuitive.
Easybrain was acquired by Stillfront Group for $640 million in 2021 — a deal that valued the humble sudoku app as one of the most lucrative properties in casual mobile gaming. That acquisition price tells you everything about how large the sudoku audience actually is.
5. KenKen
Developer: Nextoy (created by Tetsuya Miyamoto) | Released: 2008 (digital versions)
Platforms: Web (kenken.com), iOS, Android
Difficulty: Easy to very hard | Price: Free (web); app varies
KenKen combines the logic of sudoku with arithmetic. Each cage (group of cells) shows a target number and an operation (add, subtract, multiply, divide). You must fill the grid so each row and column contains unique digits AND each cage's numbers produce the target using the specified operation.
Invented by Japanese math teacher Tetsuya Miyamoto as a classroom tool, KenKen was picked up by The New York Times and has appeared in the paper since 2009. It's the rare number puzzle that genuinely improves mental math alongside logical reasoning.
6. Threes!
Developer: Sirvo (Asher Vollmer, Greg Wohlwend) | Released: 2014
Platforms: iOS, Android, Xbox One
Difficulty: Easy to learn, extremely hard to master | Price: $5.99 (no ads)
Slide numbered tiles on a 4x4 grid to combine them: 1+2=3, then matching tiles double (3+3=6, 6+6=12, and so on). Each swipe moves every tile, so positioning matters as much as math. The game ends when the board fills with no possible moves.
Threes! was the original — released months before 2048, the free clone that went viral and overshadowed it. The development team documented their 14-month design process in a public postmortem that remains one of the most cited pieces of game design writing. Despite being eclipsed commercially by its clone, Threes! is the better-designed game.
Pop culture: Won Apple Design Award 2014. The 2048 clone controversy sparked industry-wide conversation about idea theft in mobile gaming.
7. 2048
Developer: Gabriele Cirulli (independent) | Released: March 2014
Platforms: Web (play2048.co), iOS, Android
Difficulty: Medium | Price: Free
Slide tiles on a 4x4 grid to combine matching numbers: 2+2=4, 4+4=8, and so on, aiming to reach the 2048 tile. Cirulli, a 19-year-old Italian developer, built it in a weekend as a JavaScript exercise. It went viral within days, reaching millions of players.
2048 is admittedly a clone of Threes! (see above), which Cirulli has openly acknowledged. But its free availability, browser-based accessibility, and simpler ruleset gave it an explosive reach that Threes! couldn't match. It remains one of the most-played browser games in history.
8. Nonograms / Picross
Developer: Various (Jupiter for Nintendo Picross series; Nonograms Katana on mobile) | Released: 1987 (concept); digital versions ongoing
Platforms: Nintendo DS/3DS/Switch (Picross), iOS, Android (Nonograms Katana)
Difficulty: Easy to very hard | Price: Varies ($1.99–$9.99 for premium apps; free with ads)
Number clues along rows and columns tell you which cells to fill in. Solve the logic puzzle correctly and a picture is revealed. Also known as Picross, Griddlers, or Paint by Numbers, these puzzles are addictive because the visual payoff of revealing an image adds emotional reward to logical deduction.
The Picross series on Nintendo platforms (Picross S, Picross e) is the gold standard, with hundreds of puzzles and clean design. On mobile, Nonograms Katana offers thousands of free puzzles with a passionate community creating user-generated content.
9. Killer Sudoku
Developer: Various (Cracking the Cryptic, Sudoku.com, dedicated apps) | Released: Concept from 2005; digital versions ongoing
Platforms: iOS, Android, Web
Difficulty: Medium to very hard | Price: Free to $4.99 depending on app
Killer Sudoku applies the same row/column/box rules as classic sudoku but removes all given numbers. Instead, dotted cages show a sum — the digits inside must add up to that total without repeating. You solve it by combining sudoku logic with arithmetic constraint.
Killer Sudoku is the most popular sudoku variant after the classic. It's the natural next step for players who've mastered standard sudoku and want a fresh challenge without learning an entirely new game. Cracking the Cryptic's YouTube channel has driven significant interest in this variant.
10. Nerdle
Developer: Richard Mann and Marcus Tettmar | Released: January 2022
Platforms: Web (nerdlegame.com)
Difficulty: Moderate to hard | Price: Free
Included on our Daily Word Games list too, Nerdle earns a spot here because it's fundamentally a number puzzle. Guess a valid eight-character arithmetic equation in six attempts, with color-coded feedback on which numbers and operators are correct. If Wordle is for word people, Nerdle is for math people.
Teachers use it as a classroom warm-up. Multiple modes (Mini, Micro, Speed) add variety. It launched at the peak of the Wordle-variant wave and has maintained a loyal daily player base.
Quick Guide
| If you want... | Play... |
|---|---|
| The best sudoku app, period | Good Sudoku |
| No-frills daily sudoku | NYT Sudoku |
| Fiendishly hard variants | Cracking the Cryptic |
| The most popular free app | Sudoku.com |
| Sudoku + arithmetic | KenKen or Killer Sudoku |
| Addictive number sliding | Threes! (premium) or 2048 (free) |
| Logic puzzles that reveal pictures | Nonograms / Picross |
| Daily math challenge | Nerdle |
Enjoy logic puzzles? Try Pairdle — a daily word puzzle that plays more like Sudoku than Scrabble.
By Tim Nye, Logic Loft Games