Accessibility of High-Fidelity Prototyping Tools

High-fidelity prototyping tools are used by software designers and developers to iron out interface details without full implementation. However, the lack of visual accessibility in these tools creates a barrier for designers who may use screen readers, such as those who are vision impaired. We assessed conformance of four prototyping tools (Sketch, Adobe XD, Balsamiq, UXPin) with accessibility guidelines, using two screen readers (Narrator and VoiceOver), focusing our analysis on GUI element accessibility and critical workflows used to create prototypes. We found few tools were fully accessible, with 45.9% of GUI elements meeting accessibility criteria (34.2% partially supported accessibility, 19.9% not supporting accessibility). Accessibility issues stymied efforts to create prototypes using screen readers. Though no screen reader-tool pairs were completely accessible, the most accessible pairs were VoiceOver-Sketch, VoiceOver-Balsamiq, and Narrator-Balsamiq. We recommend prioritizing improved accessibility for input and control instruction, alternative text, focus order, canvas element properties, and keyboard operations.