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Change Blindness Test
Two almost identical scenes flash back and forth, and in one of them a single object has changed — it shifted colour, moved or vanished. Spot the change and tap that object before time runs out. Six rounds measure how many changes you catch, how fast, and how many wrong taps you make.
Press Start, then tap the object that changes.
About the Change Blindness Test
Change blindness is the surprising failure to notice a change in plain sight when the view is briefly interrupted. A flicker between the two scenes hides the moment of change, so even a vanished object or a recoloured shape can go unnoticed for seconds. It is one reason eyewitness accounts and driving awareness can be unreliable.
In each of the six rounds a fresh scene of coloured shapes is shown, alternating with its changed version. One object per round either changes colour, moves or disappears. Tap the object you think changed — a correct tap ends the round, a wrong tap is counted, and if no change is found within 20 seconds the round is scored as a miss.
About
The Change Blindness Test measures how quickly and reliably you detect visual alterations when two nearly identical scenes alternate with a brief blank interval. Each trial presents a pair of images that differ by a single object's appearance, position, or color, and the flicker between them masks the transition so the change is not immediately obvious. Your task is to click or tap the changing element as soon as you spot it, allowing the tool to capture both accuracy and response time across multiple trials.
How your result is scored
The result combines the proportion of correctly identified changes with the median reaction time for successful trials, producing a single composite index that reflects both sensitivity and speed. A higher index indicates you consistently notice subtle differences with minimal delay, while a lower index suggests either missed changes or slower detection. Because performance varies with fatigue, screen size, and ambient lighting, treat the score as a relative benchmark rather than an absolute ability measure.
Tips to improve
- Scan the scene in a systematic grid pattern instead of random glances.
- Focus on high-contrast edges where objects are most likely to change.
- Reduce screen glare and use a stable refresh rate to minimize visual noise.
- Take short breaks between blocks to reset attentional resources.
- Practice with slower flicker rates first, then gradually increase speed.
Related
Frequently asked questions
- How many trials does a typical session include?
- A standard session runs 20 to 30 trials, each lasting a few seconds, and takes about three minutes to complete.
- Can I pause or restart the test mid-session?
- Yes, a pause button is available, and you can restart the full sequence from the results screen.
- Does the test work on mobile devices?
- The test runs in any modern mobile browser, though a larger screen makes subtle changes easier to detect.
- Is this test used for clinical diagnosis?
- No, it is a self-assessment tool for personal insight and practice, not a medical or diagnostic instrument.