Assessments vs. Screening
The only way that dyslexia can be formally identified is by a Diagnostic Assessment carried out by a qualified assessor (i.e. a specialist teacher or educational / occupational psychologist). Screening tests can be useful, but they can only give an indication of possible dyslexic difficulties.
There are several types of screening tests available; these can be taken offline or online. Where a screening test indicates that there is a moderate to high probability of dyslexic difficulties, we would always advise a Diagnostic Assessment. This assessment will determine the precise nature of the difficulties, and how they can best be supported.