Lexicon — how big is your vocabulary?
Lexicon is a free, two-minute vocabulary-size test you run right in your browser. You are shown a checklist of about sixty words and you simply tap the ones you genuinely know. The twist: some of those words are invented pseudowords that only look real, so you cannot win by tapping everything. Lexicon subtracts your false alarms, weighs each real word you knew by how rare it is, and estimates how many English words you know in total — then shows your percentile against other speakers and a word-nerd tier, from Word Sprout to Word Wizard.
Nothing you tap ever leaves your device: the whole test and its scoring run locally, with no account, no sign-up, and no data sent anywhere. When you finish you get a shareable result card you can download or post, plus a fresh pack of words for a rematch. It is playful curiosity content — a fun estimate, not a scientific test.