English

Vocabulary Test: Real Word or Fake?

Real words and made-up ones, one at a time: do you know it? You get an estimate of how many words you know. About 4 minutes, free, no sign-up. We save scores, with your IP address and country, to build comparisons.

By the Helibrain teamReviewed by Robert, biophysics PhD candidatePublished Last reviewed

Real word or fake?

You'll see 100 words, one at a time. Some are real words, some are made up. Tap “I know it” only for words you know.

Guessing doesn't help: the made-up words catch it, and your estimate goes down. On a keyboard: F or ← for made up, J or → for I know it.

How to read your result

Your result is an estimate of how many of the 51,508 words in our list you know. We split the list into bands, from the most common words to rare ones, and check how many real words you know in each band. Made-up words catch guessing: every one you accept lowers the estimate. Large studies with tests like this put a 20-year-old native English speaker at about 42,000 words [1].

  • Words you know (estimate): the share of real words you knew in each band, corrected for guessing, times the number of words in that band, added up. We show the most likely number and a range: with only 10 words per band, the true number could be some way off.
  • Made-up words you said yes to: if you accept more than 30% of them, the result says the estimate is shaky.
  • Accuracy score: the average of the share of real words you knew and the share of made-up words you rejected, the way the LexTALE test scores it [2].
  • The band bars: how much of each band you know. Almost everyone knows the most common words; the rare bands are where people differ.

Quick facts

  • What it measures: vocabulary size, a part of crystallized knowledge: what you have learned over the years, as opposed to how fast you think.
  • Typical numbers: in a study of about one million English tests, a 20-year-old native speaker of American English knew about 42,000 lemmas (dictionary words); most people fell between 27,000 and 52,000. Between 20 and 60, the average person learns about 6,000 more [1].
  • It keeps growing: in a Dutch version played by nearly 300,000 people, age, education and knowing several languages were the strongest factors in vocabulary size [3].
  • Steady over time: short online vocabulary tests gave similar results when people took a second, different version a week or more later (r = 0.68 and 0.82 for two tests) [4].

How the test works

  1. You see one word at a time: about two thirds are real words, the rest are made up but look like real words.
  2. Tap I know it if you know the word, even roughly. Tap Made up if you don't know it or think it's fake.
  3. The test has 100 words: 70 real words, 10 from each of 7 frequency bands, and 30 made-up words. 4 practice words with feedback come first; you can skip them.

There's no clock. Our server picks a new set of words for each run and works out the result; the page never knows which words are real.

Our word list has 51,508 words: dictionary words from Wiktionary, sorted by how often they appear in large collections of text, with names, slang, rare spellings and word forms removed. We checked a sample of each band by hand and wrote the made-up words ourselves.

What affects your score

  • Guessing. Saying yes to words you only half recognize lifts the real-word count but also the made-up count, and the correction takes it back.
  • Your languages. Speakers of English as a second language score lower, and people who know related languages may recognize more rare words [3].
  • Reading and age. People who read a lot and older adults usually know more words [1][3].
  • Chance. 10 words per band is a small sample. Take the test again for a second estimate; the average of two runs is better than either one.

What this test can and can't tell you

The test estimates how many words of our list you recognize. It doesn't check whether you know their exact meaning, and it says nothing about intelligence, health or how well you write. Our list is not the list the large studies used, so compare your number with them only roughly [1]. Each language has its own list, so numbers from different languages can't be compared.

Frequently asked questions

How many words does the average person know?

A study of English vocabulary tests estimated that a 20-year-old native speaker of American English knows about 42,000 dictionary words, with most people between 27,000 and 52,000, and that people keep learning about 6,000 more words between ages 20 and 60 [1]. The Helibrain vocabulary test uses its own list of 51,508 words, so its numbers are close to these but not the same.

Why are there made-up words in the test?

Made-up words show how often you say yes without knowing a word. The Helibrain vocabulary test subtracts that guessing from your real-word answers, so honest answers give the most accurate estimate. The same idea is used in research tests like LexTALE [2].

Is this a test of English as a second language?

Not exactly. Learners can take it, and tests of this kind are used to check English proficiency [2], but the Helibrain vocabulary test reports an estimate of words known, not a language level. Expect a lower number than native speakers get; that's normal.

Can I improve my vocabulary score?

Your vocabulary grows by reading and listening to varied language over months and years [1][3]. Practice on the test itself won't help much, because each run uses a new mix of words.

Is the Helibrain vocabulary test free?

Yes. The test and your full result are free: no sign-up, no email, no payment. We save results with your IP address and country to build comparisons, as our privacy policy explains. Helibrain makes money from its app, which has a free plan and paid plans; you don't need the app for this test.

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Sources

  1. Brysbaert M, Stevens M, Mandera P, Keuleers E (2016). How many words do we know? Practical estimates of vocabulary size dependent on word definition, the degree of language input and the participant's age. Frontiers in Psychology 7:1116. doi.org/10.3389/fpsyg.2016.01116
  2. Lemhöfer K, Broersma M (2012). Introducing LexTALE: a quick and valid Lexical Test for Advanced Learners of English. Behavior Research Methods 44(2):325–343. doi.org/10.3758/s13428-011-0146-0
  3. Keuleers E, Stevens M, Mandera P, Brysbaert M (2015). Word knowledge in the crowd: measuring vocabulary size and word prevalence in a massive online experiment. Quarterly Journal of Experimental Psychology 68(8):1665–1692. doi.org/10.1080/17470218.2015.1022560
  4. Drown L, Giovannone N, Pisoni DB, Theodore RM (2023). Validation of two measures for assessing English vocabulary knowledge on web-based testing platforms: brief assessments. Linguistics Vanguard 9(1):99–111. doi.org/10.1515/lingvan-2022-0116

How we made this page: written by the Helibrain team from the studies listed above, and reviewed by Robert (biophysics PhD candidate) on 4 November 2026. We update it when the sources change.