Are free online IQ tests accurate? What one can tell you, and eight compared

What a standardized score needs

• A norm sample: a large group, sampled to represent a population by age and other characteristics, whose scores define where 100 and 15 sit.
• Controlled administration: the same instructions, timing, materials and environment for everyone, usually with a trained administrator.
• Calibrated items: each item's difficulty and discrimination measured on the sample, so that the test is neither too easy nor too hard and the items measure one underlying ability.
• A reliability estimate: evidence that the score would come out similar on another day or a parallel form, expressed as a standard error of measurement.

Professional standards for tests describe these requirements in detail. A browser result is most useful for seeing which question types you solved and where to practise next.

Eight online IQ tests, side by side

Each row below uses only what the test's own page said when we read it on 4 November 2026, and each page is linked under Sources. A cell that says not stated means the page does not say; it is not a guess, and it is not a criticism. The rows are in alphabetical order, with ours last, because the table is not a ranking. Pages change, so check the source before you rely on a cell.

How to read the table

Two columns answer most of the question in the title. The first is norms. A number on the IQ scale means something only if the page tells you whose scores set the middle at 100 and the spread at 15. Not stated is the commonest entry in that column, and our row says plainly that we have no norm sample. The second is time and setting. A 2-minute, 10-question quiz and a 25-minute, 35-puzzle test can print numbers on the same scale, but the shorter one has far less information behind its number, and none of them controls who else is in the room, what screen you use or whether you have seen the puzzles before.

The other columns tell you what kind of practice you are getting. A test built mostly from figure matrices tells you about matrices; one with verbal items depends partly on your English. A test with no time limit and one with a strict clock are measuring slightly different things even when the questions look alike.

What the table cannot tell you is which number is right. With no published norm sample behind them, two of these tests can give the same person different numbers on the same day.

For the arithmetic behind a number on the scale, see what a score on the IQ scale means.

What our practice estimate means

Our 36-question test reports how many questions of each type you solved, explains every answer, and, on a first attempt finished within 26 minutes, gives an IQ-style practice estimate. Later attempts still show the full review, without the estimate, because a second sitting of the same questions partly measures memory. For a formal IQ score, see a psychologist.

The method page shows, step by step, how the practice estimate is worked out.

Want a longer run of the same question types? The 72-question full IQ test adds a bonus part for high scorers.

How a raw count becomes an IQ-style number

A count of correct answers can be put on the familiar IQ scale with a formula. Whether that number is a practice estimate or a standardized score depends on whether a norm sample stands behind it, so check how a result is described before you rely on it.

Speed adds another distortion. Timing over the internet varies with the device, the connection and whether the page was already loaded, so a timed browser score mixes reasoning with hardware.

Why most practice sites write their own questions rather than copy a published test: which psychological tests may be reproduced.

What a browser test can report

It can report how many questions of each kind you solved, with the questions, your answers and the correct answers shown. It can tell you which kinds of rule you recognised and which you missed, which is exactly what practice needs. It can also be a fair introduction to the item formats that real tests use, so that the formats are not new on the day a real test matters.

That is what the tests under this hub do. The free IQ-style test reports a score by question type and difficulty, explains every answer and offers an IQ-style practice estimate.

When you need a real score

If a decision depends on an IQ score, the only route is a professionally administered test with a written report, confidence intervals and subscale results. Educational psychologists, clinical psychologists and, for admission purposes, some high-IQ societies administer or accept such tests. A browser result is not evidence in that setting, and no site should tell you otherwise.