What is Brain Challenge?
Brain Challenge is a free browser game with 1000 puzzle levels. Every level is one of five puzzle types, and the difficulty rises as you go: the first 100 levels use small 3×3 grids and simple sequences, while levels past 600 use 6×6 grids, longer strings and multi-step number rules.
There is nothing to install and no account to create. Your progress is stored in your browser, so you can close the tab and come back later. Every puzzle can be solved with paper and pencil — no timers tricks, no guessing penalties.
The five puzzle types
1. Odd one out
A grid of characters or shapes where exactly one cell differs — a mirrored letter, a slightly rotated shape. As levels increase the grid grows from 3×3 to 6×6 and the rotation difference shrinks from 18° to 5°. Tips for odd-one-out puzzles.
2. Hidden digit
A string of look-alike characters such as O 0 O O. Exactly one character is a digit. Longer strings and more distracting letters appear at higher levels. How to spot digits hiding in letters.
3. Number patterns
Work out the rule behind a number sequence and pick the next term. Rules range from simple addition to Fibonacci, growing gaps, squares and “×2 + 1” chains. Number sequence strategies.
4. Picture idioms
Emoji or number clues that encode a four-character Chinese idiom, such as 7️⃣ ⬆️ 8️⃣ ⬇️ for 七上八下. A fun way to pick up chengyu without flashcards. How picture idioms work · All 30 idioms explained.
5. Logic riddles
Short deduction puzzles: “Ann is taller than Ben, Ben is taller than Cat. Who is tallest?” Later levels add a fourth person and two or three premises. Solving logic riddles quickly.
Is it really free?
Yes. The game runs entirely in your browser, and there is no paid tier or locked content. Ads (when shown) keep the site running; they never block a level. If you use an ad blocker the game still works normally.
Frequently asked questions
Do I need to sign up?
No. Progress lives in your browser's local storage. Clearing site data resets it.
Can I play on my phone?
Yes. The layout is responsive, and you can add the page to your home screen from the browser menu to play full-screen.
How long does it take to finish all 1000 levels?
At roughly 20 seconds per level, about 5–6 hours of play. Most people spread it over weeks.
Can I share a specific level?
Yes — the URL includes the level number. Send someone a link like ?level=601 and they will land on that puzzle.
Why is there a timer?
It keeps sessions short and focuses attention. Running out of time only reveals the answer — you can retry the same level immediately.