How do I decide whether an image needs alt text or can be treated as decorative?

Start with the image’s job on that page, not with how interesting or detailed it looks. Ask: “If this image were absent, would someone lose information needed to understand the page or use it?” The text alternative depends on the image’s usage, context, and content. Informative images need alternatives conveying their essential information; images that only decorate and add no important information can have an empty alternative; functional images need an alternative describing their function. [S1]

A practical first pass is:

1. It communicates relevant information: write informative alt text.
2. It performs an action or serves as a link: describe its function or purpose.
3. It adds no information and is purely decorative: an empty alternative may be appropriate.

Don’t decide from the picture alone. The same image might be informative in one place and decorative in another.

Suppose a page uses a photo of a red umbrella. These are hypothetical examples, not claims about any particular image:

• In an article explaining how to identify the umbrella mentioned in a lost-property notice, the color and object may matter. A possible alternative is: “Red umbrella left near the entrance.” Use it only if those details match the supplied context.
• If the photo is a link that opens an umbrella product page, describe the link’s purpose, such as “View red umbrella details,” if that is what the link does.
• If it sits behind a heading as decoration and conveys no information needed to understand the page, an empty alternative may be appropriate.

The key is not to narrate every visible detail. Select what helps someone understand the image’s role in that specific page. If nearby text already explains the relevant information, check whether the image adds anything meaningful before writing a second description.

Don’t invent a purpose or infer details the page context does not establish. Check the nearby heading, caption, link text, and surrounding copy, then ask the person responsible for the page what the image is meant to communicate or do. Context is part of the decision, so guessing from appearance alone can lead to an alternative that misses the image’s role. [S1]

Until the context is clear, record a question rather than approving guessed wording. For example: “Please confirm whether this image illustrates the process, links to another page, or is only decorative.” If it is a chart, diagram, or image containing text, ask what information readers are expected to take from it. The guidance supports choosing alternatives by purpose and essential information, but it does not establish the intended meaning of a particular picture. [S1]

Yes. Fill in the context before drafting an alternative:

“Page or section: [where the image appears] Image’s role here: [information / action or link / decoration / unclear] What readers need from it: [essential information or function, if any] Decision: [informative alt text / function-focused alt text / empty alternative / ask for context] Draft or question: [proposed wording or clarification request]”

Worked hypothetical example:

“Page or section: [event registration page] Image’s role here: [unclear] What readers need from it: [not confirmed] Decision: [ask for context] Draft or question: [Does this image communicate event details, link to registration, or serve only as decoration?]”

Once its role is confirmed, write a short description that covers the relevant information or function—or choose an empty alternative if it is only decorative. Read it alongside the page: it should convey the image’s needed meaning or purpose without introducing unsupported details. The final decision depends on the actual page context. [S1]