The stomatal assay is a common practice in plant physiology research that represents a significant bottleneck to research pipelines which relies upon experts to record stomatal features accurately; requiring significant researcher time and investment. StomaAI (SAI), the bottleneck breaker, is a reliable, user-friendly and adaptable tool for auto-measuring stomatal density and pore features (width, length and area) from microscope images with human-level accuracy via deep computer vision. SAI has been initially calibrated and deployed for the model plant Arabidopsis (dicot) and the crop plant barley (monocot grass). For other plant species, we encourage researchers to contribute to SAI or to contact us and collaborate to increase its utility. SAI online demonstration is hosted at https://sai.aiml.team/, and the full local application is publicly available for free on GitHub through https://github.com/xdynames/sai-app. Further information, including user instructions, can be found in our published paper (DOI:10.1111/nph.18765).