Free or paid IQ test: what changes?
Being free or paid does not tell you whether an IQ test is good: the method does. There are free instruments built by researchers, and paid tests that give a number with no margin of error. Before paying, check what you get and whether the charge repeats.
In this article
Is a free IQ test always worse?
No. One example is ICAR, the International Cognitive Ability Resource, a set of reasoning items built by researchers and used, according to the project page at TU Dortmund University, by several hundred research groups. It is free, but the same page says it is intended for academic use only: it is not a test for the public to get an IQ.
On the other hand, many free tests online are built to entertain: few questions, no explained norm and a high number at the end. What separates them from serious tests is the method, not the cost.
What does a paid test usually add?
Usually a fuller report: results by area, a review of the questions, a certificate and sometimes exercises. That can be worth it, but paying does not change the quality of the measurement itself.
Look carefully at the billing model. Some sites charge a small entry amount that turns into a subscription after a few days. There is nothing wrong with that model when it is clear, but you need to know before paying.
How to compare, criterion by criterion?
| Criterion | What to look for |
|---|---|
| Number of questions | Stated before you start; very short tests err more |
| Norm | Who you are compared with, and whether the comparison is by age |
| Margin of error | A range, not just a number |
| Method | A page that explains how the score is calculated |
| What is paid | Stated before you answer or, at the latest, before you pay |
| Billing | One-time or subscription, and how to cancel |
| Limits | Whether the site says what the result is not for |
The detailed list of signs is in How to tell if an online IQ test is reliable.
How does it work at IQNorth?
This page belongs to IQNorth, and our test is one of the paid ones. Answering the 40 questions is free. The IQ number, the 95% range and the full report are paid. How renewal works and how to cancel are on the help pages, which you can read before paying: Does the subscription renew automatically? and How to cancel your subscription.
See also: IQNorth or myIQ.
Sources
- TU Dortmund, Department of Statistics. International Cognitive Ability Resource (ICAR). Accessed Nov 5, 2026. https://sms.statistik.tu-dortmund.de/en/research/projects/completed-research-projects/international-cognitive-ability-resource-icar/
- Condon, D. M., & Revelle, W. (2014). The International Cognitive Ability Resource: Development and initial validation of a public-domain measure. Intelligence, 43, 52–64.
