The Behavioral Avoidance Test (BAT) for spider phobia is a widely-used diagnostic tool assessing fear by measuring avoidance behavior. However, BATs require considerable preparation and different BAT protocols across studies hamper result comparability. To address this, we have developed an open-access online BAT (vBATon). We validated its efficacy in measuring avoidance and eliciting anxiety/disgust by comparing it to a real-life BAT. Spider-fearful (N = 31) and non-fearful (N = 31) individuals completed both tests on separate dates. Both tests successfully distinguished between spider-fearful and non-fearful individuals. Crucially, equivalence tests confirmed that vBATon captures avoidance, anxiety, and disgust equal to the real-life BAT. We found moderate to high correlations between vBATon and (1) the real-life BAT and (2) self-report measurements of spider-fear. Our study suggests that vBATon is a valid, standardized, efficient and user-friendly alternative to real-life BATs for measuring spider fear in both research and clinical practice. (Access to vBATon: https://spider-phobia-research.com/wp-content/uploads/2023/07/vbaton_pub/)