Automatic Alt Text

Alternative text for images that is automatically generated by artificial intelligence systems using computer vision and natural language processing. Platforms like Microsoft PowerPoint, Facebook, and Twitter have incorporated automatic alt text features to increase image accessibility coverage. While automatic alt text can be better than having no description at all, research has shown it frequently suffers from inaccuracies, vagueness, incomplete descriptions, and biases — particularly for non-photographic images like charts and screenshots. Critically, the presence of automatic alt text can anchor human authors to lower quality descriptions, as they treat the AI output as a baseline rather than writing from scratch.