20 of the most informative questions from all four domains, chosen adaptively and scored on the 100-average scale. Most people finish in under 20 minutes and see their score instantly.
Answer recorded: . Memory items can't be repeated.
WELL DONE
Quick assessment complete.
0/20Questions answered
00:00Time used
YOUR QUICK ESTIMATE · 0/20 CORRECT · 00:0051Extremely low · higher than about <1% of takersLikely range 40–62. A 20-question estimate has a wider margin than the full test.
SHARPEN THE ESTIMATETake the full test for your four domain scores and a range about 36% narrowerStart the 60-question test →
Prototype scoring against preliminary norms until the live item-response calibration is connected.
WHY 20 QUESTIONS IS ENOUGH
Every extra question buys less precision than the last
Measurement error shrinks with the square root of test length. Going from 5 to 20 questions cuts the margin sharply; going from 20 to 60 tightens it further, but by less. Drag to see it.
Likely range around a score of 11099–121± 10.9 points
8597.5110122.5135
5 Qs
±18
10 Qs
±14
20 Qs
±11
40 Qs
±8
60 Qs
±7
Illustration: 95% margins from the Spearman–Brown formula, assuming the 60-item test has reliability .95. Real margins depend on item calibration; adaptive selection narrows them further.
HOW THE 20 ARE CHOSEN
Not the first 20 questions. The 20 that tell us most.
A short test only works if every item earns its place. Switch between a naive short test and ours to see the difference.
difficulty →
115
Logical reasoning
Spatial intelligence
Verbal comprehension
Working memory
Each row is the 15-item bank for one domain, easiest to hardest. Lit cells are the items a 20-question test would use.
SPREAD ACROSS THE RANGEItems at every level, so the test can place anyone
Picking items across the whole difficulty range, then adapting to your answers, means the test spends questions near your level, whether that is 85 or 135. Each item is also chosen for high discrimination: how sharply it separates people just above and just below its difficulty.
✓Measures from the low end to the very top✓High-discrimination items only✓Adapts to every answer
SHORT FORMS ARE NOTHING NEW
Psychologists have trusted brief IQ tests for decades
Clinicians, employers and researchers routinely use short forms when a full battery isn't practical. Here is how ours sits among them.
1930s–Wonderlic Personnel Test
50items12minutes
Employer screening classic, famously used at the NFL combine until 2022.
1994Raven's APM short form
12items~15minutes
Arthur & Day's 12-item version of the Advanced Progressive Matrices.
2011WASI-II, 2 subtests
2 testsitems~15minutes
Clinicians' standard brief IQ: Vocabulary plus Matrix Reasoning.
2014ICAR-16
16itemsuntimedminutes
Open research short form from the International Cognitive Ability Resource.
TodayThis quick test
20items20minutes
Four domains, adaptive, IRT-scored, 9 languages, free.
Item counts and timings as published by each test's authors; WASI-II time is the typical administration time for its two-subtest form.
WHAT MOVES A QUICK SCORE
With 20 items, conditions matter more
One lapse costs 1 of 60 items on the full test but 1 of 20 here. Toggle your conditions to see what could be dragging the number.
YOUR TEST CONDITIONS3/6Your score may come out low
Fix the switched-off items above if you can, or treat the result as a floor rather than your best estimate.
QUICK OR FULL?
Pick by what you want to know
QUICK TEST · 20 QS · 20 MIN
“Roughly where am I?”
✓A fast first read of your level✓Under 20 minutes, one sitting✓No signup, no email, instant score✓Checking before committing to the full hour
FULL TEST · 60 QS · 60 MIN
“What exactly am I good at?”
✓Four separate domain scores✓Narrower confidence range✓Age-normed comparison, country comparison✓PDF report, certificate, permanent result link✓Your most reliable estimate
Your IQ estimate on the standard scale (reported from 40 to 160), your percentile among takers, and a classification from extremely low to very superior. No signup, no email, nothing to unlock.
Embretson, S. E., & Reise, S. P. (2000). Item Response Theory for Psychologists. Lawrence Erlbaum.
Brown, W. (1910). Some experimental results in the correlation of mental abilities. British Journal of Psychology, 3(3), 296–322 (Spearman–Brown prophecy formula).
Wechsler, D. (2011). Wechsler Abbreviated Scale of Intelligence – Second Edition (WASI-II) Manual. Pearson. Short-form IQ estimation.
20 questions. Your number. Now.Free, instant, no signup.