— Comparison
Core Brain vs 123test.com
123test offers a free quick IQ test and a paid Pro version. Different approach, different audience.
| 123test.com | Core Brain | |
|---|---|---|
| Format | Free 22-min classical IQ test (verbal, spatial, numeric subtests), paid version costs $29.95 for detailed report | Free 20-min test, $15 one-time unlock for full normed report with six-axis breakdown |
| Methodology | Classical test theory (CTT) | IRT 3PL Bayesian MAP |
| Confidence interval | No | Yes (95% CI) |
| Six-axis breakdown | No | Yes |
| Time | 15-30 min | 20 min |
| Cost | $29.95 | $15 |
Verdict
123test is well-established but uses classical scoring rather than item response theory. Core Brain uses modern IRT psychometrics (same as the WAIS), which produces more accurate estimates from fewer items.
Try Core Brain
20 minutes, six cognitive axes, full normed IQ with 95% confidence interval. $15 unlock or take a promo code if you have one.
Which should you take?
Take 123test.com if:
- You prefer classical (older) test methodology
- You want a longer, more comprehensive single test
Take Core Brain if:
- You want a calibrated 20-minute test with real IRT scoring
- You want to see WHICH cognitive axis you're strongest in, not just a single number
- You want a 95% confidence interval on your score (the mark of a real psychometric test)
- You want a downloadable certificate