A screenshot in your tutorial shows exactly where to look. A banner links to a product guide. A small graphic separates two sections. All three are images, but they serve different purposes.
Start with one question when writing alt text for blog images: What would someone miss if they couldn’t see this image? The answer tells you whether to describe a detail, name a destination, or let a decorative image pass without an announcement. The W3C image decision tree is a useful reference when the choice is unclear. W3C
Describe the detail your screenshot teaches
Suppose your tutorial shows an image settings panel with the Alternative Text field highlighted.
Too vague: “WordPress screenshot.”
More useful: “Image settings panel with the Alternative Text field highlighted.”
The second version names what matters to this lesson. You can leave out unrelated controls. Keep the actual instruction in the article as well: “Select the image and look for the Alternative Text field in its settings.” That way, readers can follow the step without seeing the screenshot.
Use the same check for a chart or a dense worksheet. If someone needs several figures or relationships to understand your point, explain them in the article or provide a text version. A short image description can identify the chart while the article supplies the details. W3C
Name the destination when the image is the link
Imagine a banner is the only thing a reader can select to open your product guide. “Blue shield on a dark background” describes its appearance but leaves the link’s purpose unclear. “Read the SentryPC guide” tells readers where the link goes. If the banner opens the provider’s product page instead, use “Visit the SentryPC product page.” W3C
Check the actual destination before writing the label. If the banner contains essential wording that readers can’t find anywhere else, put that information in nearby text. For example, if the graphic is the only place that mentions a resource requires an email signup, add that detail beside the link.
Leave purely decorative images quiet
A flourish between sections or a background graphic may add style without adding information. For a purely decorative HTML image, use an empty alternative: alt="". That is different from omitting the alt attribute altogether. W3C
If an audit flags a missing attribute, check what the image does on that page before deciding how to fix it. An instructional screenshot needs a useful description. A decorative divider needs an empty alternative. If the image is the only content of a link, give the link a meaningful name through the image’s alt text. W3C
Use captions and alt text for their own jobs
A visible caption can explain why the example matters: “The revised signup form places the offer directly above the button.” Alt text can identify a meaningful visual detail that the caption and nearby text don’t already convey. Read both together and check whether each adds something useful.
If you’ve already included the essential detail in the article, you can keep the alt text brief. For a redundant image that adds no information or function, an empty alternative may be appropriate. W3C
Your Blueprint Action Step
Choose one published post and review three images. For each one, decide whether it teaches a detail, opens a destination, or adds decoration. Write the alternative that fits, then check the published page. If you’re resolving an audit warning, rerun the check after publishing your changes.
Start with one image. Read the surrounding paragraph, check what the image does, and write the words someone would need to get the same information or take the same action.

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