Intelligence in minimally verbal children on the autism spectrum (AS) is at risk of being underestimated. The present study investigated testability and cognitive profile of preschool autistic children using conventional tools and strength-informed tools. Fifty-two AS children and fifty-four typical children matched on age (31-77 months) were assessed. Testability increased with age in both groups, was generally lower in AS children, but not related to their test performance. Typical children performed significantly better than AS children on conventional tools, but performance of both groups was similar on strength-informed tools. Differences of performance across tests were much greater in the AS group. These results emphasize the heterogenous, yet characteristic, cognitive profile in preschool children, and introduce the usefulness of flexible testing.