Questions, answered plainly

Expercepth publishes visual puzzles: hidden object scenes, optical illusions, memory challenges, pattern puzzles and spot the difference, plus articles that explain how they work.

One tile in the grid is a slightly lighter shade. Tap it to move to the next round. The difference gets smaller and the grid gets bigger as you go. Three wrong taps end the run.

No. Everything runs in your web browser on a phone, tablet or computer.

Your visual system makes fast guesses about light, depth and edges before you are aware of them. Knowing the trick does not switch those guesses off, which is what makes illusions so stubborn.

No. You can read articles and play the warm-up without one. An account gives you a username, a profile title and a place on the leaderboard.

Log in and open your Profile from the menu. You can change your username, phone number, title and password there.

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Send a note through the contact page or email [email protected]. Corrections and puzzle ideas are welcome.

Expercepth Bot sits in the bottom corner of every page. It answers questions about the site, accounts and texts.