You can find free, online cognitive tests on the websites for Food for the Brain and the University of Virginia, as of 2015. Both websites feature multiple tests that allow visitors to take cognitive tests online and receive results.
Find free, online cognitive tests on Food for the Brain by clicking Alzheimer's Prevention on the home page and then clicking Take the Test on the next page. The next page prompts the user to accept the terms and conditions and start the test.
Find online cognitive tests on the University of Virginia's website by typing "Cognitive Aging Laboratory" in the search bar, clicking the Search icon and then clicking The Cognitive Aging Laboratory on the next page. On the resulting page, click Online Cognitive Tests under the Resources tab.