Visual content optimization for AI is increasingly important as systems become multimodal. Here’s what works:
Alt text best practices:
Don’t describe WHAT the image is. Describe what INSIGHT it provides.
Bad alt text:
“Bar chart showing revenue by quarter”
Good alt text:
“Bar chart showing Q4 revenue growth of 25% year-over-year, outperforming Q1-Q3 averages by 12 percentage points”
The second version gives AI extractable information it can cite.
Optimal length: 80-125 characters. Long enough to convey insight, short enough to be useful.
The processing chain:
AI systems use multiple signals:
- Alt text (primary for non-multimodal queries)
- Caption text
- Surrounding paragraph text
- Filename
- ImageObject schema
- Visual analysis (for multimodal systems)
Optimize all of them, not just one.