Guru Smart's "Sudoku Puzzle: Brain Games" is a solid classic app with unlimited undo, optional auto-check and number-first input. Its age rating notes advertising, and its listing sells Sudoku Pro plans and hint packs (2 Hints, $0.99). If paying for help is what bothers you, Sudoku Royale's hints are free and teach the technique instead of filling the cell. Brainium Sudoku and nerByte Sudoku also explain their hints and remove ads with one payment, and Good Sudoku is the pick if Expert has become too easy.
Guru's app has 92,448 US ratings since 2020. Its listing describes four levels (Easy, Medium, Difficult, Expert), 100 new puzzles a week, notes that update themselves, an eraser, per-level stats and a dark theme. The same developer makes Crossmath. This page is for players who like how it plays but not how it charges, or who want more from it than four levels.
The App Store facts
| App | Price and ads | Paid options listed | US rating | Last update | Devices |
|---|---|---|---|---|---|
| Sudoku Puzzle: Brain Games | Free, ads, in-app purchases | Sudoku Pro - 1 Week $2.99, Sudoku Pro $7.99, Monthly Subscription $2.99 | 4.9 from 92,448 ratings | September 4, 2026 | iPhone, iPad, Mac, Apple Vision |
| Sudoku Royale | Free, no in-app purchases | None listed | 4.8 from 11 ratings | October 23, 2026 | iPhone, iPad, Mac, Apple Vision |
| Brainium Sudoku | Free, ads (remove for $11.99) | Remove Ads $11.99 | 4.8 from 161,164 ratings | June 29, 2026 | iPhone, iPad, Apple Vision |
| nerByte Sudoku | Free, ads (remove for $7.99) | Sudoku No Ads $7.99 | 4.7 from 24,061 ratings | February 25, 2025 | iPhone, iPad, Mac |
| Good Sudoku | Free, in-app purchases | Full Game Unlock $4.99 | 4.2 from 1,332 ratings | July 21, 2025 | iPhone, iPad, Mac, Apple Vision |
| Sudoku.com | Free, ads (remove for $14.99) | Sudoku.com No Ads $14.99 | 4.8 from 1.87 million ratings | October 16, 2026 | iPhone, iPad |
From each app's US App Store listing, checked October 26, 2026. Prices and paid items change, so check the listing before you buy.
Hints: what they do and what they cost
The hint is where these apps differ most. "Hint packs sold" reads each app's in-app purchase list on the App Store.
| App | What a hint does, per its listing | Hint packs sold |
|---|---|---|
| Guru Sudoku | Helps when you are stuck; the listing does not say it explains | Yes: 2 Hints, $0.99 |
| Sudoku Royale | Names the technique and the cell, not the number; links to the lesson | None, nothing is sold |
| Brainium Sudoku | Teaches the logic behind the answer, with animations | None listed |
| nerByte Sudoku | Explains the requested hint step by step | None listed |
| Good Sudoku | Reads your notes to find the technique you are missing | None listed |
| Sudoku.com | Guides you when you are stuck | None listed |
Free hints that teach: Sudoku Royale
Sudoku Royale (our app) has no ads, no purchases and no subscription, so there is no Pro tier and no hint shop. In Practice, a bulb lights up after about 90 seconds without progress. Tap it and it shows which cell to look at and which technique solves it, say a hidden single or a pointing pair, and links to the lesson. You still place the number yourself. If you want the logic behind the hint in general, our guide to sudoku hints covers it.
Number-first input carries over: in Sudoku Royale you can arm a number and tap cells, much like Guru's tap-and-hold lock, or hold a number and swipe. Our page on number-first vs cell-first input explains when each is faster. What does not carry over: undo, the option to switch auto-check off (Sudoku Royale always checks and rejects a wrong number), and the eraser. Hints also need an internet connection and only appear in Practice.
Keep the toolbox, pay once: Brainium or nerByte
Brainium Sudoku is the best known teaching hint. Its listing says the hint button provides the technique you need to make progress, with animations and visuals, and it adds auto-fill and auto-clear notes, an auto-check option and number painting, which is close to Guru's number lock. Ads go with one Remove Ads purchase at $11.99. See Sudoku Royale vs Brainium for how its hints compare with ours.
nerByte Sudoku lists explanatory step-by-step hints, five levels from Fast to Expert, adjustable number size, landscape play and unrestricted offline play. Sudoku No Ads is $7.99.
When Expert is not hard enough
Guru's Expert is its ceiling. Good Sudoku lays out exactly which techniques each of its five levels requires, and its hardest puzzles need X-Wing-style fish such as Swordfish and Jellyfish. It is a $4.99 Full Game Unlock, not a subscription. Sudoku Royale adds Master and Extreme above Expert, each unlocked by a few solves at the level below, and a Dojo for timed drills of single patterns.
When to stay with Guru
- You use unlimited undo. Sudoku Royale has none, and the listings of Brainium and Good Sudoku do not mention it.
- You like finding your own mistakes. Guru lets you turn auto-check off; Sudoku Royale does not.
- You rarely use hints. Then the hint packs never matter, and a free app with a familiar layout is fine as it is.
- You want the app in your language. Guru's listing shows 71 languages. Sudoku Royale's app is in English only.
The short version
Free hints that teach, no ads, nothing for sale: get Sudoku Royale. Explained hints plus undo and a one-time ad removal: Brainium or nerByte. Harder puzzles: Good Sudoku. The head-to-head is in Sudoku Royale vs Guru Sudoku, and the full list is on the comparisons hub.
Frequently Asked Questions
Do you have to pay for hints in Guru's Sudoku Puzzle: Brain Games?
Its App Store listing sells hint packs (2 Hints, $0.99) next to its Pro plans. The listing does not say how many free hints you get.
Which sudoku app has free hints that explain the move?
Sudoku Royale's hints are free: they name the technique and the cell and link to the lesson. Brainium Sudoku and nerByte Sudoku also describe explained hints; both are free with ads and sell a one-time ad removal.
Does Sudoku Royale have number-first input like Guru?
Yes. You can arm a number and tap cells, hold a number key and swipe along the bar, or tap a cell and pick a number from a pop-up.
Does Sudoku Royale have undo?
No. Every number is checked when you place it and a wrong one is rejected, so mistakes never stay on the board, but there is no undo.
Which alternative is harder than Guru's Expert level?
Good Sudoku's hardest puzzles need techniques like Swordfish and Jellyfish. Sudoku Royale has two levels above Expert, Master and Extreme.
Is Guru Sudoku the same developer as Crossmath?
Yes. Both are published by Guru Smart on the App Store.