- Alt text becomes facts in answers. On a comparison task the agent lifted a rating straight from alt text — “The image alt text mentions ‘Defaqto 5-star’ and ‘Which? Recommended Provider…’. I’ll note these details and verify their accuracy.” A badge, chart, or award graphic with rich alt text can put its claim into the AI answer.
- No alt text means invisible. With
alt=""or a meaningless filename, the agent reads the filename and gives up: “It seems to be a vector graphic (‘awardwinning-360x140.svg’)… likely just decorative, so I’ll skip it.”
AI agents read your image alt text as content
Peec’s Deep Research logs (Jun 2026) — ChatGPT’s agent reads image alt text as page content, lifting ratings straight from alt attributes; images without alt text are skipped as decorative.
Image alt text is the only thing ChatGPT’s Deep Research agent can read from an image — and it treats it as page content. Peec’s recorded session logs (full study, Jun 2026) show every image rendered into the read text as a marker carrying its alt attribute.
Two documented behaviors (Jun 2026):
