The Reflex Lab
Nine free reaction games and memory tests that measure you in the browser — and are not polite about the result.
Free in your browser — no download, no sign up. Scores stay on your device.
Speed
- Reaction Time Test — A real reaction time test — click the moment red turns green, five trials, scored as the median so one lucky twitch does not count.
- CPS Test — A click speed test with 1, 5, 10, and 60 second modes — clicks per second, total clicks, and your best per mode saved in your browser.
- Spacebar Counter — Press the spacebar as many times as you can in 5 to 60 seconds — a big live counter, presses per second at the end, and a no-timer mode for counting anything at all.
- Aim Trainer — Thirty targets, one at a time, as fast as you can click them — average ms per target, total time, and an accuracy score that counts every miss.
- Typing Test — A timed typing speed test — 15, 30, or 60 seconds of common words, scored the standard way: WPM from correct characters, plus accuracy and raw WPM.
Memory
- Number Memory Test — The classic digit span test — a number flashes, you type it back from memory, and it gets one digit longer every time you're right.
- Visual Memory Test — A visual memory test: tiles flash for a second, you click them back from memory, and the grid grows until your three lives run out.
- Sequence Memory Test — A Simon-style sequence memory test: repeat a growing pattern on a 3x3 grid until one wrong click ends the run — your score is the longest sequence you held.
- Chimp Test — Numbers flash on a grid, then hide — click them in order from memory, the way the chimpanzees at Kyoto did it.
Every test on this page is over in seconds. The attention span test is the two-minute version: tracking, recall, and vigilance, scored out of 100.
How the lab works
- Pick a shelf. Speed holds the reaction time test, the CPS test, the spacebar counter, the aim trainer, and the typing test. Memory holds the number test, the visual memory test, the sequence test, and the chimp test.
- Every test starts the moment you click it: free, in the browser, no download, no sign up, no account. Most take under two minutes.
- Your scores save to your browser's local storage, so your best and your history are waiting next visit — on this device, visible to nobody but you.
- Each test tells you plainly what it measures and what it cannot. A browser can time your clicks; it cannot see your monitor's lag, and it will not pretend otherwise.
Why scores differ between devices
A reaction time measured in a browser is really three numbers added together: your nervous system, your input device, and your display. The lab only controls the last measurement point — the browser timestamp of your click or key press. Everything upstream adds delay the page cannot see: a 60Hz monitor redraws roughly every 16.7 milliseconds, so the stimulus itself can appear up to a frame late, and a wireless mouse or a touchscreen adds its own lag before the browser hears about your reaction.
This is why the same person scores differently on a gaming desktop and a three-year-old phone, and why we treat every score as a measurement of you-plus-your-hardware. The number is consistent and repeatable on one setup; it is not a laboratory reading, and no browser test anywhere is, whatever their marketing says.
How to compare fairly (same device, same day)
If you want a comparison that means something, hold everything constant except the person: same test, same device, same input method, same sitting. Hardware differences between two laptops can be larger than the difference between two humans, so a phone-versus-desktop rivalry is really a hardware benchmark with people attached.
For tracking yourself over time, trust the median of several attempts rather than your single best — one lucky anticipation is not a reflex. And expect honest day-to-day drift: sleep, caffeine, and time of day all move reaction scores by real amounts, which is a finding about you, not a bug in the test.
What the lab will not tell you
You will not see percentiles here, because we have not run a norming study on the general population and we are not going to invent one. You will not see claims that these games train your brain, sharpen your mind, or hold off aging — practicing the chimp test makes you better at the chimp test, and the research on transfer beyond that is not something a games site should be paraphrasing at you.
What you get instead is the measurement itself, stated plainly, saved locally, and repeatable whenever you want a rematch with yourself. The sibling Attention Span Test at /attention-test/ runs on the same policy: it measures two minutes of your attention and declines to diagnose anything.
FAQ
What is the Reflex Lab?
A set of nine free human-benchmark-style tests that run in your browser, organized into two shelves: Speed (reaction time, clicks per second, spacebar, aim, typing) and Memory (numbers, visual patterns, sequences, and the chimp test). Everything is instant, nothing needs an account, and your scores stay in your browser's local storage. The Attention Span Test at /attention-test/ is part of the same instrument family — longer, quieter, equally blunt.
Are these tests accurate?
They are honest, which is the version of accurate a browser can offer. The tests use the browser's own event timestamps, which are precise and consistent on one device — but your monitor's refresh rate and your mouse or touchscreen add tens of milliseconds the page cannot see. So your score is a reliable measurement of you on your setup, good for tracking progress and settling arguments on the same machine. It is not a clinical instrument, and we will not dress it up as one.
What is a good reaction time?
Research literature generally puts simple visual reaction time around 200 to 300 milliseconds for adults, with most studies clustering near 250. Human Benchmark, the best-known site of this kind, has published a median across its users of about 273 milliseconds — a number that includes everyone's device lag, which is why it runs slower than laboratory figures. We do not publish norms of our own, because we have not measured a population and made-up percentiles are lies with decimal points.
Which test should I start with?
The reaction time test — it is the classic, it takes thirty seconds, and every other score makes more sense once you know your baseline. From there: the CPS test if you want something frantic, the typing test if you want something useful, and the chimp test if you want something humbling.
Can I compare scores with friends?
Yes, with one rule: same test, same kind of device. Hardware differences can outweigh human differences, so a phone score versus a desktop score settles nothing. Scores live in each person's own browser — there are no accounts or global leaderboards here — so the honest protocol is one device, passed around, best median wins.
Why is it called the chimp test?
It recreates a working-memory task from research at Kyoto University's Primate Research Institute, where a chimpanzee named Ayumu learned to recall the positions of briefly shown numerals — and in the published experiments the chimpanzees outperformed the adult humans tested against them. Our version shows you numbers, hides them, and asks you to tap them in order. Most people develop a new respect for chimpanzees within about four rounds.
Will these games improve my brain?
They will improve your scores on these games, which is not the same thing. Practice effects on a specific task are real and you will see them in your history; broad claims about training memory or intelligence are exactly the kind of thing we refuse to print. If your reflexes or memory genuinely worry you, that is a question for a doctor, not a burger website.
Is the Reflex Lab free?
Yes. Every test is free in your browser — no download, no sign up, no account, no trial that expires. Your results are stored in your browser's local storage and never leave your device.
The Reflex Lab is part of burger fun, next door to the Number Lab and a directory of weird browser games.