Here are some online psychological tests that can be used as part of an Autism Spectrum Disorder (ASD) self-diagnosis.
Simon Baron-Cohen is well known for his research into Autism, some of it is quite controversial (particularly the “Extreme Male Brain” theory which is widely rejected in the Autism community). There are some interesting tests based on his work though, GlennRowe.net has some online tests for Systemising Quotient, Empathy Quotient, Autism Spectrum Quotient, and the Mind in the Eyes test .
There is an online Alexithymia test, note that the Alexithymia.us site has no other useful content other than the test . It would be useful if someone would create a better site about Alexithymia. I’d be happy to provide hosting for a forum if someone would do the moderation.