Decide what the reader needs to know
A caption can identify a place, explain a circumstance or add information outside the frame. Alt text helps communicate the information or function of an image when the image is not seen. The appropriate wording depends on the image’s role on that page.
Write the caption and the text alternative together, then compare them. If they repeat the same information word for word, consider whether the surrounding text already provides what the reader needs.
Describe purpose rather than every detail
W3C distinguishes informative, decorative and functional images. A meaningful photograph generally needs a useful description; a purely decorative image can use an empty alternative. An image acting as a link also needs a clear destination or purpose.
For a portfolio, describe the main visual information that contributes to the project. Avoid turning the alternative into a list of keywords, camera specifications or subjective praise. A concise description is often more helpful than an inventory of everything visible.
Read the page without the pictures
Move through the page as a sequence of headings, text and links. Check that the project remains understandable and that image links have meaningful labels. Also test whether the caption stays beside the correct photograph on a small screen.
Keep this review in the publishing checklist. When an image changes, revisit its caption and alternative rather than inheriting the text from the previous photograph. Accessibility works best as part of editing, not as a final mechanical field to fill.
Keep in mind
- Give captions a contextual role
- Describe the image’s purpose
- Avoid keyword lists
- Update text when images change