Lexical Decision Task
— Free Online
Five-minute browser-based reaction-time test of word recognition and semantic priming. Instant accuracy and RT profile. No signup needed.
What you'll get
Each trial presents a letter string for a fraction of a second. Your task is to decide as quickly and accurately as possible whether it is a real English word or a made-up nonword. From your responses we compute:
- Mean reaction time on word vs. non-word trials
- Accuracy for each trial type and your lexicality effect (non-word RT minus word RT)
- A lexical-access index with a percentile against the available reference sample
- Word-frequency band breakdown — how your RT varies by how common the words are
- Semantic priming effects at short and long SOAs
Common questions
How long does it take?
About five minutes. The task runs forty trials with a brief fixation cross before each one and short feedback after your response. Most people finish in under six minutes including the instructions.
Is it really free?
Yes. The Lexical Decision Task is free to take with no signup, and you see your reaction-time and accuracy profile immediately at the end. Full clinician-grade reports are part of the clinician and researcher offering, which is set up by arrangement — it has nothing to do with whether you can run this task.
How accurate is browser-based reaction time?
More accurate than people expect. The task calibrates your monitor's refresh rate at startup and schedules every stimulus on a frame boundary, so prime durations and stimulus-onset asynchronies land within roughly one frame (~16 ms) of their nominal value. That is well within the precision needed to recover the standard lexicality and priming effects reported in the published literature. It is not a substitute for a research lab running EEG-locked timing, but for individual-level estimates it is well-validated.
Can I retake it?
Yes. You can run the task as many times as you like. Reaction-time scores are noisier than self-report scales, and a small amount of practice effect is normal across the first one or two attempts.
What is the difference between this and a research-grade LDT?
The paradigm is the same — a fixation, a letter string, a word/non-word judgment, a measured response time. Research-grade administration adds an isolated room, a chin-rest to fix viewing distance, a dedicated response box rather than a keyboard, and often EEG to mark stimulus onset to the millisecond. For population-level inference and individual self-knowledge, the browser version recovers the same effects; for high-stakes clinical or experimental work, supervised lab administration is still the standard.