🧠Cerebite

Vocabulary Size Test

Check every word whose meaning you know. Be honest — a few made-up words are hidden in the list to keep everyone truthful.

Your vocabulary is about
0
words

Tap a word to mark it as known. When you're done, press "See my result".

How the estimate works

The English lexicon is sampled in frequency bands — from the 1,000 most common words down to extremely rare ones. You see a few random words from each band; the share you know in a band estimates how much of that whole band you know, and adding the bands up gives your total. Checking made-up words lowers the estimate, so honesty pays. Every retake draws a fresh random sample, so your number may vary by a couple of thousand — that's normal for a 2-minute estimate.

More to try

Ñ

Spanish Vocabulary Test

🧪

Vocabulary Check (verified)

📝

Vocabulary Quiz (by level)

한

Hangul Quiz (Korean Alphabet)

⚡

Reaction Time Test

🎯

Aim Trainer

Frequently asked questions

How accurate is this vocabulary test?
It's a statistical estimate from a 2-minute sample, not a full exam — expect a margin of a few thousand words. Taking it several times and averaging gives a steadier number. Research puts adult native speakers at roughly 20,000–35,000 words, which matches what this method reports.
Why are there made-up words in the list?
They're an honesty check. Self-reported tests are easy to inflate by checking everything — but fake words catch that, and each one you check lowers your estimate. If you avoid them all, your result is trustworthy.
What counts as "knowing" a word?
Check it if you could give at least one meaning of the word when you see it. You don't need to spell it from memory or use it actively — recognizing the meaning is the standard used by vocabulary researchers.
How many English words do I need for each CEFR level?
Commonly cited benchmarks run from about 1,000 word families at A2, to around 2,500–4,000 at B2, and 8,000 or more at C1–C2, where reading newspapers and novels feels natural. Match your estimate from this test against those bands to see roughly where you sit — and what the next milestone is.
How fast does vocabulary grow naturally?
Native-speaking children pick up roughly 1,000 word families a year through their school years, mostly from reading — which is why vocabulary keeps expanding well into adulthood. For learners, steady reading plus deliberate study can approach that pace. Retest here every month or two; visible growth is normal on that timescale.
Does vocabulary size keep growing with age?
Yes — unlike many cognitive measures, vocabulary typically keeps increasing through adulthood and often peaks quite late in life, because every year of reading and conversation adds new words. So whatever your age, your estimate here isn't a ceiling: it's a snapshot of a number that's still moving.