Choose the learner track if you want to check your CEFR vocabulary level. It compares your result with A1–C2 benchmarks, including the B2 vocabulary range and C2 vocabulary range. Choose the native-speaker track if your goal is a broader English word-count estimate.
Choose Your Track
Our English vocabulary test offers two separate tracks depending on your goal. Both use the same adaptive engine, but draw from different word banks and produce different result formats.
Tells you your CEFR level (A1–C2) and estimated vocabulary size in word families. Ideal if you're learning English and want to know where you stand on the international proficiency scale.
Start CEFR test →Tests vocabulary from everyday words up to rare literary and academic terms. Reports a model-based word-family range and category profile; independent validation is pending.
Start native test →How the Test Works
Most vocabulary tests ask you to tick words you recognise from a list. This approach can encourage overclaiming. Our two-phase format is designed to reduce that bias by asking for a definition after a word is recognized.
- You see a word. The test shows you one word at a time and asks whether you know it.
- If you claim to know it, you must define it. For words you say you know, the test immediately asks a multiple-choice comprehension question. This catches overclaiming and keeps scores honest.
- The algorithm adapts using Bayesian IRT. It evaluates your ability across a 2-Parameter Logistic (2PL) Item Response Theory model. It selects the next word that maximizes the mathematical **Fisher Information** for your current estimated level. The test dynamically halts when the Standard Error of Measurement (SEM) falls below $\le 0.22$ (usually in 12–20 questions).
- You receive your result. A model-based vocabulary-size range, a CEFR-oriented vocabulary band for learners, and a list of missed words with definitions. These are educational estimates, not official placements.
Why two-phase testing? Recognition-only formats can be affected by overclaiming when people select words they only partly recognise. Definition confirmation is intended to reduce that bias, although this implementation still requires independent validation.
What Your Score Means
For English learners (CEFR track)
| CEFR Level | Vocabulary size | What this means in practice |
|---|---|---|
| A1 — Beginner | 500–1,000 words | Basic survival phrases; very simple conversations |
| A2 — Elementary | 1,000–2,000 words | Routine tasks; simple descriptions of background and routine |
| B1 — Intermediate | 2,000–3,500 words | Travel situations; simple connected text on familiar topics |
| B2 — Upper-Intermediate | 3,500–6,000 words | Fluent conversation; complex texts; professional use |
| C1 — Advanced | 6,000–9,000 words | Flexible use in academic and professional contexts |
| C2 — Proficient | 9,000–12,000 words | Near-native; nuanced expression; literary texts |
For native speakers
| Score range | Tier | Typical profile |
|---|---|---|
| Under 15,000 | Developing | Younger speakers; limited reading history |
| 15,000–22,000 | Functional | Average adult with moderate reading |
| 22,000–30,000 | Proficient | College-educated adult, regular reader |
| 30,000–38,000 | Advanced | Avid reader; graduate-level education |
| 38,000+ | Exceptional range | High model-based estimate; population percentile not validated |
For full context on what these numbers mean and how they compare to population averages, see our research guide to average vocabulary size.
The Science Behind the Test
Our word bank uses frequency information informed by Brysbaert & Keuleers (2016), a large English vocabulary study based on more than 220,000 participants. The research helps organize the sampled words, but it does not independently validate this site's algorithm or make a short result directly comparable to the study population.
The adaptive algorithm uses a 2-Parameter Logistic (2PL) Item Response Theory (IRT) model, Bayesian Expected A Posteriori (EAP) estimation, and Fisher Information item selection. These techniques are established in educational measurement, but their use does not by itself validate this implementation or prove equivalence to a high-stakes standardized test.
For learners, the site maps vocabulary estimates to internal CEFR-oriented bands for study planning. CEFR proficiency is a broader, skills-based construct, so a vocabulary-only result must not be interpreted as an official CEFR placement.
Thematic Lexical Profiling
To provide a multidimensional view of your English proficiency, your performance is categorized into five distinct thematic domains: Academic, Business, Conversational, Literary, and Collocations. Your mastery across these domains is computed dynamically and visualized on an interactive SVG Radar Chart, allowing you to easily identify your lexical strengths and weaknesses.
Who Should Take This Test?
English learners preparing for exams
If you're preparing for IELTS, TOEFL, Cambridge (FCE, CAE, CPE), or another English proficiency exam, the test provides a quick CEFR-oriented vocabulary estimate and a missed-word study list. It does not determine readiness for an official exam, which also assesses skills beyond vocabulary.
Native speakers curious about their vocabulary
How broad is your receptive vocabulary? The native-speaker track samples words across frequency bands and returns an indicative model-based range. It is useful for study planning, but has not been independently calibrated as a population percentile or high-stakes exam score.
Students and teachers
Vocabulary size is one of the strongest predictors of reading comprehension, academic performance, and writing quality. The test can serve as a pre- and post-measure for vocabulary instruction, or as a diagnostic tool to identify vocabulary gaps before starting a course or reading programme.
Language researchers and enthusiasts
For anyone interested in lexicography, linguistics, or the psychology of language, the test offers a hands-on demonstration of how vocabulary size is measured — and a personal data point to compare against the published literature.
How Our Test Compares to Other Vocabulary Tests
| Test | Method | Result format | Time |
|---|---|---|---|
| vocabulary-test.com | Adaptive two-phase (recognition + definition) | Model-based range; validation pending | 8 min |
| Recognition checklists | Self-reported word recognition | Sample-dependent estimate | Usually short |
| Text profiling tools | Analysis of words in a supplied text | Vocabulary profile of the text | Varies |
| Fixed multiple-choice tests | Same item set for each user | Test-specific band or raw result | Varies |
| Word-association measures | Written associations | Instrument-specific research measure | Usually longer |
The two-phase design requires a definition confirmation for claimed words, which is intended to reduce overclaiming bias found in recognition-only formats. How effectively it does so, and how closely scores correspond to the Brysbaert (2016) benchmarks, still requires an independent validation study.
Tips for Getting a More Consistent Result
- Be honest. If you're unsure whether you know a word, say no. The algorithm is calibrated for honest responses, and inflating your answers reduces accuracy.
- Don't skip words you actually know. If you're confident you know a word, say yes even if you can't immediately recall a perfect definition. The definition question will confirm it.
- Do not use a dictionary. Looking up words during the test defeats the purpose. The value of the result comes from measuring your current, unassisted vocabulary.
- Take the test when you're alert. Fatigue significantly affects word recognition, particularly for lower-frequency words. Mid-morning is the optimal time for most people.
- Take it more than once. Vocabulary size fluctuates slightly depending on your current state. Taking the test on two or three separate occasions and averaging the results gives you the most reliable estimate.
Ready to Test Your English Vocabulary?
Free · Adaptive · Instant results · No sign-up required
Start the free vocabulary test →Frequently Asked Questions
How can I test how many English words I know?
Start the free test and choose the learner or native-speaker track. The adaptive questions sample words around your current ability, then return an estimated vocabulary range. For context before you begin, see the guide to how many English words you may know.
How does the English vocabulary test work?
The test employs a two-phase design. In Phase I (Recognition), you mark known words from a checklist containing decoy words to filter out overclaiming. In Phase II (Definition), a mathematically rigorous 2-Parameter Logistic (2PL) Item Response Theory (IRT) adaptive loop presents definition questions. The system computes your latent ability using Bayesian Expected A Posteriori (EAP) estimation and selects questions that maximize Fisher Information. It dynamically stops when the Standard Error of Measurement (SEM) is $\le 0.22$ (usually in 12–20 questions) and builds a multidimensional diagnostic Lexical Profile Radar Chart.
How accurate is an online vocabulary test?
Accuracy depends on the word sample, item calibration, response honesty, and how “knowing a word” is defined. Our test uses published vocabulary research, overclaim detection, and a 2PL IRT Bayesian framework, but this specific implementation has not yet been independently validated against an external criterion test. Treat the result as an indicative range, not a fixed-error measurement.
What is a good score on an English vocabulary test?
For native speakers: 20,000–28,000 word families is average; 28,000–35,000 is strong; above 35,000 is excellent (top quarter of native speakers). For English learners: 3,500–6,000 words corresponds to B2 (conversational fluency); 6,000–9,000 to C1 (advanced); 9,000–12,000 to C2 (near-native). See our full guide to average vocabulary size by age and education for detailed benchmarks.
Can I use this test to find my CEFR level?
Yes. The learner track is specifically calibrated to the A1–C2 CEFR scale. After completing the test, you receive your estimated CEFR vocabulary level alongside your word count, so you can compare your result against the official CEFR benchmarks. For a detailed guide to what each level means, visit our CEFR vocabulary guide.
How long does the vocabulary test take?
Most users complete the test in 6–10 minutes. The test's EAP engine continuously measures accuracy; if standard error falls below a reliable threshold (SEM ≤ 0.22), it halts dynamically — often concluding within 12–20 questions of Phase II.
Is the vocabulary test free?
Yes, completely free. No account required. Both the native speaker track and the CEFR learner track are free and require no sign-up. Results are shown immediately after the test ends.
What language is the vocabulary test in?
All questions are in English. The test measures English vocabulary only. Both native English speakers and English learners can use it — they simply select the appropriate track at the start of the test.
Will my vocabulary test results improve with practice?
Vocabulary size grows primarily through reading, not through taking vocabulary tests. However, reviewing the missed-word list after each test and studying those words is a highly targeted way to improve — you're focusing exactly on the words just beyond your current knowledge boundary, which is the most efficient zone for learning.
Related Resources
- Average Vocabulary Size by Age and Education — research benchmarks to compare your score against
- Native Speaker Vocabulary — what 20,000–35,000 word families looks like and how natives differ from advanced learners
- Vocabulary by Age — word-count milestones from age 1 to 18+
- CEFR Vocabulary Levels Guide (A1–C2) — what each CEFR level means and what vocabulary it requires
- SAT & GRE Vocabulary — the academic and literary vocabulary on the native speaker track
- Methodology & Science — how the adaptive algorithm and calibration work