The aim of this study was to assess text generation and text transcription of children and youth with Autism Spectrum Disorder (ASD, n = 67) and Typically Developing (TD) peers (n = 67). Participants (80.6% male, ages 9–14) produced a free-style handwriting task analysed for written content and handwriting legibility and speed. Findings showed children and youth with ASD perform significantly poorer than TD peers for written content and handwriting legibility and speed. For children and youth with ASD, poor handwriting legibility predicted poor written content. For TD peers, fast handwriting predicted good written content. Collapsing both groups, ASD group membership negatively predicted written content, after controlling for handwriting legibility and speed. Practical implementations for the educational context are provided.