Are Online Psychological Tests Reliable?

Dr MS Broudy
Updated on October 3, 2022

How often do you come across online ads for psychological tests that claim to measure your intelligence, personality, or some other trait? Of course, it’s enticing to think that you can find out intriguing things about yourself in just a few minutes. It’s certainly easier when compared with having to consult with a mental health professional. It almost seems too good to be true. But is it a scam? Are these tests valid and reliable? Let’s find out.

psychological testing online

The Validity and Reliability of Psychological Tests

Psychological tests need to have two things: validity and reliability. Validity means that a test measures what it says it measures. Reliability means that a test will give you the same results if you repeat the test over time. Established psychological tests, such as the Minnesota Multiphasic Personality Inventory (MMPI) and the Wechsler IQ tests, have undergone strenuous evaluation to establish their scientific soundness. Some of these tests can be taken online and are likely to be just as accurate whether you take them on your computer or with paper and pencil. But what determines whether a test is valid and reliable?

How to Know If a Test Is Valid

The validity of a psychological test is normally rigorously reviewed by scientists in the field. Of course, this doesn’t apply to online psychological tests, so here are several factors to consider when questioning their validity.

  • First, take a look at the questions. Do they make sense? This is called face validity. Ask yourself if there are a lot of red flags or if it seems like the real deal.
  • A valid psychological test is not going to be very short and should have a minimum of 15 questions.
  • Does the test compare favorably with another respectable test? If so, you have what is called concurrent validity.
  • Are test items based on a particular theory? Valid measures possess construct validity. This means they measure a construct as defined by a specific hypothesis. For example, the well-known Millon Clinical Multiaxial Inventory (MCMI) is based on Theodore Millon’s theory of personality.

How to Know If a Test Is Reliable

An online test’s reliability can be gauged by taking into account the following variables:

  • All online tests are self-report. This is a reliability problem because you never know if someone is telling the truth.
  • As with validity, the longer the test, the more reliable it is.
  • The environment in which you take the test should be consistent over time. With online tests, you never know.
  • Clear and detailed test instructions improve reliability.
  • Changes in a person’s state can lead to less reliable results.

Different Types of Psychological Testing

Whether or not a test delivers on its promise depends on the type of test and your expectations. Are you taking an IQ quiz in the hopes that you will find out your exact IQ, or are you just looking for a general idea of your intelligence? Do you believe that an online personality quiz is going to unlock your innermost secrets? Are you looking for a mental health diagnosis? Although an online test might promise the world, it is important to understand the type of test you are taking to manage your own expectations.

Psychological Assessment

An assessment is not the same as a test, although the words are frequently used interchangeably. In psychological terms, an assessment uses a variety of measures, including tests, interviews, and personal history to establish a diagnosis. It is important to note that a diagnosis is usually derived from multiple sources, not one test. Since no test is perfect, it is dangerous to draw conclusions from a sole measure.

Psychological Tests

Psychological tests have been created to measure many variables, including IQ, vocational preferences, mental health disorders, and overall personality. Accurate tests undergo rigorous standards to establish reliability and validity, usually over many years. Valid tests are rarely freely available online and need to be given and interpreted by a mental health professional.


Screenings are developed to recognize a possible problem. They may be created by the same people that created a larger test and include some of the same questions. Since they do not have as many questions, they are inherently less valid and reliable. It is fairly simple to create a screening measure that lacks sound psychometric properties, although some, such as the Beck Depression Inventory (BDI), are considered to be somewhat accurate.

Almost anyone, however, can put together some questions and call it a screening measure. People need to watch out for disreputable sources of information. Screenings should only be used to determine the need for further evaluation rather than for a definitive conclusion. Many of the tests and quizzes you see online fit into this category.

How to Know If an Online Psychological Test Can Be Trusted

When you encounter an online psychological test, whether it’s labeled as a test, quiz, screening or assessment, there are a few things you should keep in mind when trying to determine how much you should trust the results. Think about the following before deciding whether or not to take the test and rely on what it tells you:

Consider the Source

Does this test come from a reputable organization or person? Is it endorsed by a credentialed professional? Many online therapy platforms ask clients to complete questionnaires when they first sign up. These too, are only as reliable as the therapy providers that issue them. If unsure, take a few minutes and look them up online. It might immediately clear up a lot of questions.

Is It Free?

Most well-researched tests are not free. In fact, they might cost a lot of money. Free psychological tests or quizzes are automatic red flags.

Test Length

As discussed, reliability and validity improve with more test questions. Providing an accurate IQ or diagnosis in ten questions is not possible.


It is always a good idea to compare an online test to others you may have taken before, especially if you know for a fact that they were trustworthy. Reliable and valid tests should provide similar conclusions. If you take a test that gives you wildly different results, that may indicate a problem.

Trust Your Intuition

What is your gut telling you? Does this seem to be real or is this “quiz” meant to be simply for entertainment purposes?

In Summary

As mental health awareness continues to gain traction, more online psychological tests will inevitably be created and disseminated. Some are well-studied while others are simply clickbait. A good rule of thumb is to be naturally skeptical and do your own research to find out if they are trustworthy. Most importantly, always consult with a professional about the interpretation of any online psychology test results.


Dr MS Broudy

MS Broudy is a psychologist, writer, and consultant. He has a Ph.D. in Clinical Psychology and a master’s degree in Social Psychology. He has spent over 20 years providing therapy and assessment services for a diverse set of clients. MS specializes in writing about mental health, parenting, and wellness. He has his own blog,, where he writes about psychological issues.

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