The academic, daily-living, and social challenges all students face during university transition can become magnified for many autistic students, who might struggle to adapt to changes in their social network structure (SNS) and perceived social support (PSS). This study assessed the development, feasibility, and convergent validity of a novel online tool (Social Network and Perceived Social Support--SNaPSS) designed to quantitatively and qualitatively evaluate SNS and PSS during university transition. SNaPSS demonstrated good feasibility for completion amongst autistic students (Study 1, n = 10, 17-19 years), and adequate convergent validity against other PSS, autism symptom severity, and social anxiety measures amongst autistic (n = 28) and typically developing students (Study 2, n = 112, 17-19 years). Broader implications of SNaPSS to measure SNS/PSS are discussed.