A speeded classification game. One item appears between two labelled category bins and you send it to the bin where it belongs. The bins change every round, and one wrong answer ends the streak.

Why do the bins keep changing?

A fixed rule turns into a reflex within a dozen rounds and stops exercising anything. Re-reading the bins each round keeps the categorisation deliberate · that re-check is the skill.

What makes high difficulty hard?

The category pairs move semantically closer · fruit versus other food, instrument versus tool. When the categories share a boundary, the fast intuitive answer starts to be wrong, and you have to check membership properly at speed.

Do I need to read any language to play?

The items are pictures, so mostly no · but the bin labels are words, translated into all 25 languages.

How does my progress save?

Your best streak is stored locally in your browser. Sign in to sync it across devices.

Speed Sort · どっちの箱？ · 日本語

One item, two bins · tap the category each thing belongs to before the rule shifts under you

Sort each item into the category bin where it belongs. JavaScript required.

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