Sudoku Royale vs Guru Sudoku: Undo, Hints and Paid Plans

Sudoku Puzzle: Brain Games by Guru Smart is the more forgiving app: unlimited undo, auto-check you can use or ignore, notes that update themselves and a small 6x6 grid for warming up. It pays for that with ads (its App Store age rating says it contains advertising), Sudoku Pro plans and packs of hints sold for money. Sudoku Royale has no undo and always checks your numbers, but it has no ads, nothing to buy, and free hints that teach the technique instead of filling in the cell.

Both apps are classic sudoku at heart. The question is whether you want a relaxed app with every safety net, or a stricter one that tries to make you a better solver.

The App Store facts

From each app's US App Store listing, checked October 26, 2026. Prices and paid items change, so check the listing before you buy.

Feature by feature

Undo and auto-check: the biggest difference in feel

Sudoku Puzzle: Brain Games's listing leans on safety nets. "Did you make a mistake? Of course, there are undo and hints functions!" It offers unlimited undo, an eraser, auto-check that marks mistakes as you go, and notes that update themselves when you fill a cell. You can experiment, guess, and back out of a dead end.

Sudoku Royale works the other way. Every number is checked the moment you place it, and a wrong one is simply rejected, so a mistake never sits on the board. There is no undo and no switch to turn checking off. Notes are yours to write, though placing a number clears that digit from the notes in its row, column and box. Some players find this cleaner, because there is never a wrong board to unwind. Others miss undo, especially for notes. If undo is the feature you cannot give up, Sudoku Puzzle: Brain Games is the better fit.

Hints you buy versus hints that teach

The App Store lists hint packs for Sudoku Puzzle: Brain Games: 2 Hints $0.99, 15 Hints $4.99, 50 Hints $9.99. That tells you hints are rationed and topped up with money. Its paid plans, listed as Sudoku Pro - 1 Week $2.99, Sudoku Pro $7.99, Monthly Subscription $2.99, Sudoku Pro - 1 Month $9.99, sit alongside them; the listing does not say which of these remove ads.

Sudoku Royale's hints are free, but they are not a shortcut. In Practice, when you have made no progress for about 90 seconds, a bulb lights up. It marks the cell to look at and names the move, such as a pointing pair or an X-Wing, then links to the lesson for it. You still place the number yourself. The Journey teaches those techniques in order, and the Dojo drills them against the clock. Hints need a connection and appear only in Practice.

Difficulty

Sudoku Puzzle: Brain Games has four levels, from Easy to Expert, and its listing calls them balanced for a fresh start through to advanced players. Sudoku Royale has six. Master and Extreme sit above Expert and unlock after a number of solves at the level below; the hardest puzzles call for techniques like X-Wing and XY-Wing. If you have finished Sudoku Puzzle: Brain Games's Expert puzzles comfortably and want the next step, that is where Royale adds something. Our picks for advanced players go further.

Where Sudoku Puzzle: Brain Games is the better pick

• You want undo. Unlimited undo is in its listing; Sudoku Royale has none.
• You want notes filled in for you as you go. Its note mode updates itself.
• You want a smaller grid. The 6x6 board suits children and first-timers. Royale is 9x9 only; see sudoku variants for other formats.
• You want the app in your language. It lists 71 languages. Royale's app is in English.
• You want a proven app. It has been out since 2020, with 92,448 US ratings.

Where Sudoku Royale is the better pick

• No ads, no plans, no hint packs. Nothing in the app costs money.
• Two levels above Expert. Master and Extreme for players who have outgrown four levels.
• A structured way to improve. Lessons, drills and a coach that replays positions from your own games.
• A daily puzzle with a leaderboard. Compare your time with friends and the world, and replay missed days from the archive.

Which should you choose?

If you like to play loose, undo freely and lean on auto-check, stay with Sudoku Puzzle: Brain Games, or pay for its plan if the ads bother you. If you are tired of being asked to pay for hints and want the puzzles to push you a little, try Sudoku Royale. More options are in our alternatives to Guru Sudoku, the best sudoku apps for beginners and the full list of comparisons.