Can I retake an IQ test?

You can retake an IQ test, but the second administration will overestimate your true ability due to practice effects. Effect sizes for repeat administration are typically 0.3 to 0.5 standard deviations on most batteries, larger if the test-taker explicitly studied items between administrations. Test publishers recommend a minimum interval of 6 to 12 months between retest administrations to allow practice effects to dissipate, and clinicians often switch to an alternate form (e.g., WAIS-IV → Stanford-Binet 5) for retests to minimize the practice effect. For online screeners, you can retake at any time, but you should expect inflated scores on subsequent administrations.

This question comes up frequently from users of free online IQ tests and from people considering whether to pursue a clinical evaluation. The full answer depends on context — what the score will be used for, how recently the test was administered, and what other information is available. The brief answer above captures the broad consensus from the published research literature; the linked deep-dive articles cover the underlying evidence in more detail.

Related considerations include the standard error of measurement on the relevant test, the population the test was normed against, and the specific cognitive abilities the test samples. A score is much more informative when interpreted alongside these contextual variables than when reported as a bare number.

If this answer raises further questions, see the related FAQ entries listed in the sidebar and the longer-form articles on the same topic in the article library. The site is designed to provide layered depth: the FAQ entries offer concise answers, the deep-dive articles offer the underlying research, and the score-interpretation pages tie the abstract concepts to specific result bands.