How to Write Photo Alt Text That Helps People Understand Your Images

You have chosen a photograph, written a caption, and are almost ready to share it. Then a field asks for “alt text.” What belongs there: the caption again, a list of keywords, or a description of every detail?

Start with a simpler question: what would someone need to know about this picture if they could not see it? Alt text is a short text alternative that helps convey an image’s meaning. Screen readers can use it to make visual content understandable. The best description reflects why the photograph is there, not just everything inside the frame. 1 3

Portrait used as an image-description example.

Start with the photograph’s job

A portrait on a professional biography has a different purpose from the same portrait in an article about dress patterns. On the biography, the person’s verified name and relevant context may matter most. In the styling article, the floral dress may be the useful detail.

Before writing, ask why you chose this image. Is it introducing a person, showing an activity, demonstrating a detail, or communicating an atmosphere? W3C’s image guidance emphasizes that purpose and surrounding context determine the appropriate text alternative. 1

For the portrait above, a useful description could be: “Woman in a floral dress standing with her hands on her hips among tall grasses.” It identifies the subject, setting and relevant appearance without inventing her identity or story.

Describe the important details, then stop

A helpful starting pattern is subject + action or position + meaningful context. You do not need to use all three if the picture’s purpose is simpler.

For a real family photograph, “Two children laugh together while their father holds their hands” can communicate more than “Beautiful family photo.” For a close-up in an article about clothing texture, “Detail of a cream cable-knit sweater” may be enough.

These are examples of possible descriptions, not accounts of studio clients. Choose words that are accurate for the actual image you are sharing.

Harvard’s accessibility guidance recommends keeping alt text short, usually one or two sentences, and focusing on key elements rather than every tiny detail. You generally do not need to begin with “image of” or “picture of.” Identify an illustration as an illustration when that distinction matters. 3

Keep the caption and alt text useful in different ways

A caption might explain the occasion, give a credit, or share what made a moment meaningful. Alt text communicates the relevant visual content. Simply copying a long promotional caption into the alt-text field can bury the information a reader needs. 3

Consider the still life below. Its visible caption identifies it as an editorial example. Its text alternative can describe the mug, notebook and flowers. Neither needs to repeat the whole paragraph around the picture.

For an article about a writing routine, the mug and open notebook might be the important details. For a flower-arranging tutorial, the yellow flowers and vase would deserve more attention. The same image can need different wording in different contexts. 3

Editorial illustration. An imagined still life used to practice image descriptions; not a studio portfolio photograph.

Do not turn the description into an advertisement

“Best photographer, luxury photography, amazing portraits” does not tell a reader what is in the photograph. Neither does a filename such as “IMG_2048.” Describe the image’s useful meaning in ordinary language.

Avoid assuming someone’s occupation, relationship, feelings or identity from appearance alone. Include a person’s name only when it is verified, relevant and appropriate to share. If the scene is on a public website, do not add a child’s school, exact location or another private detail just because you happen to know it.

Alt text should not disclose information you would otherwise keep out of the public post. Separately, make sure you have the necessary permission to publish the image itself; a careful description does not replace that permission.

Know when a photograph needs a different approach

Not every website image needs the same treatment. A meaningful photograph usually needs a short description. A purely decorative image, or one whose information is fully repeated in nearby text, can use an empty alt attribute when the website supports that treatment. An empty attribute is an intentional choice, not the same as forgetting the field. 2

If an image alone acts as a link or button, its text alternative should communicate the destination or action. If important words appear only inside an image, provide that information as accessible text too. W3C’s decision tree helps distinguish these situations. 2

Do not mark a portfolio photograph decorative merely because it looks attractive: the photograph may be the page’s main information. And do not apply a decorative-image rule indiscriminately to every picture you share.

Try a three-photo description challenge

Choose one portrait, one everyday detail and one photograph of an activity. Write a short description for each, then read it without looking at the image. Would someone understand the detail that made you choose that picture?

The takeaway: describe what matters, keep it accurate, and let the page’s purpose guide the words. Which of your recent photographs becomes easier to understand with one thoughtful sentence?

If you are planning images for your business, explore personal-branding photography or contact Suzanne Claire Studios to discuss where your photographs will be used.

References

For more examples, read W3C’s Informative Images and alt Decision Tree, plus Harvard’s guide to helpful alt text.