Box Brain Sudoku

New on the App Store

Twelve kinds of sudoku.
Hints that teach.

Classic when you want the familiar. Killer, Thermo or Kropki when you want something new. And a hint that shows you why, not just what.

Download on theApp Store Try a puzzle here first ↓
  • iPhone
  • iPad
  • iPhone Duo
Play it right here

Nine cells left. Can you finish it?

Tap a cell, then a digit. Stuck? Tap Hint: like in the app, it names the technique and shows you why the move works.

Try a skin Studio

Twenty skins in the app, and you can try any of them for a whole game before you buy.

Classic · Easy00:00

Pick an empty cell to start.

12 ways to play

One calm app, twelve kinds of sudoku

Every puzzle has exactly one solution and can be solved by logic alone. Difficulty is rated by the techniques a puzzle needs, so Hard means hard.

  • Classic

    Every row, column and 3×3 box holds 1 to 9 once.

  • Killer

    Dashed cages show the sum of their digits, with no repeats inside.

  • Jigsaw

    Odd-shaped regions take the place of the 3×3 boxes.

  • Thermo

    Digits climb from the bulb to the tip of each thermometer.

  • Arrow

    The digits along an arrow add up to the number in its circle.

  • Sandwich

    Clues give the sum of the digits between the 1 and the 9.

  • Kropki

    White dots join consecutive digits, black dots join a digit and its double.

  • Greater Than

    Signs between cells tell you which digit is bigger.

  • Diagonal

    Both long diagonals also hold 1 to 9 once each.

  • Hyper

    Four extra shaded boxes also hold 1 to 9.

  • Anti-Knight

    The same digit can't sit a chess knight's move away.

  • Even-Odd

    Shaded squares hold even digits, circled cells hold odd ones.

Take the tour

Calm on the surface. Deep underneath.

12 kinds of sudoku: a Killer puzzle Hints that teach: an XY-Wing hint explained Two dailies, every day: the daily calendar Beautiful, day and night: Thermo in the Neon skin Make it yours: try any skin for a game Your day at a glance: dailies, weekly challenge and goals See yourself improve: times, streaks and badges Made for everyone: accessibility setups Made for iPhone Duo: folded or open
Two dailies, every day

The same puzzles for everyone

A Classic and a featured mode every day. Keep your streak, with a streak saver for the day life gets in the way.

  • A weekly Expert challenge and monthly goals that earn an exclusive skin.
  • Achievements and Game Center leaderboards.
  • Challenge a friend with a link to the same puzzle and see who is faster.
Made for every screen

iPhone, iPad and iPhone Duo

On iPhone Duo the board fits folded or open, and your game carries on as you fold, unfold or turn it. On iPad and the open Duo, the board and keys sit side by side in landscape. A home-screen widget shows today's dailies at a glance.

The same Jigsaw puzzle on iPhone Duo, folded and open
iPhone Duo: folded or open, the board always fits.
iPad: room for the board, the keys and your notes.
Accessibility settings with VoiceOver, large text and colour-blind setups
Made for everyone

Play it without seeing the board

Full VoiceOver support: every cell reads its clues, and you can hear a row, column or box and enter, note or erase digits by ear. Read aloud speaks each move without a screen reader.

  • One-tap setups for low vision and colour blindness.
  • Shapes that never rely on colour alone, and a free High Contrast skin.
  • Support for Bold Text, larger text and Reduce Motion.
  • Braille sheets for embossers and swell paper, free for everyone.
Fair pricing

Free to play. Pay once if you love it.

No account, no energy, no subscription. The free version shows a small banner and never a full-screen ad you didn't ask for.

Free

$0
Plenty to play every day, no time limit
  • Unlimited Classic
  • Both dailies, every day, and the last 7 days
  • The weekly challenge, monthly goals and achievements
  • One free puzzle of every other mode
  • 3 explained hints per puzzle, and more for a short video
  • Lessons for every technique, and a first practice set
  • Studio, Night Lab and High Contrast skins, and a free trial of every other skin
  • Challenge links, Game Center, iCloud sync and the widget
  • Every accessibility feature, Read aloud and braille sheets

Pro Best value

$9.99
One-time, not a subscription
  • Unlimited play in all twelve modes
  • No ads, ever
  • Unlimited explained hints
  • The full daily archive
  • All twenty skins
  • Printable puzzle books with answer keys
  • Explained mistakes, fill all notes, colour marks, stats export

Skins pack

$2.99
One-time, for just the looks
  • Every skin unlocked, from Zen to Cyberpunk
  • Try any skin for a game first

Accessibility is never behind a paywall. Purchases restore on every device signed in to the same Apple Account. Prices are in US dollars and vary by country.

Private by design

No account and no servers holding your data. Progress stays on your device and in your own iCloud, with a backup file for a new phone.

Print and share

Share your solve as an image. With Pro, print puzzle books as a PDF in any mode and difficulty, with an answer key.

Eight languages

English, Spanish, Portuguese, German, French, Italian, Japanese and Korean.

Think inside the box.

Free on the App Store for iPhone, iPad and iPhone Duo.

Download on theApp Store