Games
Four quick browser games that measure something real: how fast you type, how quickly you react, and how much you can hold in your head. Your best scores are saved on your own device — no account, no leaderboard full of strangers.
Flagship
Typing Battle
Share a link, race the same text, watch both progress bars move in real time. A genuine peer-to-peer connection — never a simulated opponent.
Measure your WPM and accuracy in 15, 30 or 60 seconds.
Race a friend on the same text, live, from a shared link.
How fast are your reflexes? Measure it in milliseconds.
Repeat a growing sequence. How many can you hold?
Why these four games?
Each one measures a real, repeatable thing, finishes in under a minute, and works the same on a phone as on a laptop. The typing test gives you a number you can actually train against. Typing Battle turns that number into a race. The reaction test uses the browser’s high-resolution clock rather than a rough timer. And the memory game maps neatly onto the classic research on short-term memory span.
Are the scores stored anywhere?
Only in your own browser. Personal bests live in localStorage on the device you played on, and you can wipe them at any time from the privacy page. DO101 does not run a leaderboard, so there are no invented high scores to chase.