Question 1

What makes image alt text actually useful, not just present?

Accepted Answer

Useful alt text conveys the same information a sighted user gets from the image in context. Bad alt text: 'photo.jpg' or 'image of person'. Good alt text: 'A woman in a red hard hat reviewing blueprints at a construction site.' The test: if someone hears the alt text read aloud and then looks at the image, do they feel they already understood it?

Question 2

When should I use empty alt text (alt='') on an image?

Accepted Answer

For purely decorative images that add no information (icons used as decoration, background textures, stock photos that are only visual filler), use alt='' (empty string). Screen readers skip images with empty alt attributes, which is actually the correct behavior — it avoids forcing users to hear 'decorative star icon' 20 times per page.

Question 3

How long should alt text be?

Accepted Answer

WCAG guidelines don't specify a maximum, but the practical convention is under 125 characters — roughly a sentence. Screen readers often pause after 125 characters. For complex images (charts, infographics), use alt text for a brief description and provide a longer text description in the page content or a linked text alternative.

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