How do I make a visual instruction usable for someone who cannot see the image?

Start with the image’s job in this particular instruction. If the drawing teaches an action, make the text alternative state that action. W3C guidance says an informative image’s alternative should convey its meaning, not necessarily describe it literally; for an instructional diagram, a short alternative can give the instruction. [S1] [S2]

For example, assuming the drawing shows a spout being pushed into the lid, a useful draft might be: “Push the spout into the lid until it sits in place.” That example is a placeholder: confirm the wording against the actual product and approved instructions. Avoid a purely visual caption such as “A close-up drawing of a spout and lid” if it does not tell the reader what to do.

Use the short alternative for the visual’s main instructional point, then put the full sequence in the surrounding instructions if the image contains more information than a short phrase can carry. W3C recommends providing complex image information elsewhere in text, and says more extensive instructional-diagram information can go in the main text or another suitable text equivalent. [S1] [S2]

For a hypothetical diagram with three actions, the nearby text could say:

1. Place the spout above the lid opening.
2. Align the spout with the opening.
3. Press it into place, following the product’s verified instructions.

A concise alternative could then be: “Align and fit the spout into the lid; steps follow.” Treat this as a writing pattern, not product-specific directions. Check that the nearby steps really do explain the information the diagram contributes.

Ask what the image does in that context. If it adds no important information, W3C guidance says a decorative image should have an empty alternative. If it is functional, convey its function rather than merely describing its appearance. [S1]

So, if a picture is only decoration beside complete written instructions, it may not need extra descriptive wording. If an icon opens a guide, wording such as “Open the assembly guide” communicates its purpose more clearly than “book-shaped icon.” These are editorial examples; confirm that the label matches what the control actually does. The same image might be informative in one context and decorative in another, so judge its role on the page rather than by its appearance alone. [S2]

Fill in this worksheet for each image, then read the page as if you could not see it:

Visual-reference text worksheet

• Where does the image appear? [section or instruction]
• What does it help the reader understand or do? [purpose]
• Is it informative, functional, decorative, or complex here? [role]
• Short text alternative, if needed: [main instruction or function]
• Information that needs to appear in nearby text: [steps, labels, relationships, or other essential details]
• Check: Can the reader understand the instruction without relying on the image?

For a hypothetical spout diagram, you might write: “Purpose: show how the spout fits the lid. Short alternative: ‘Fit the spout into the lid opening.’ Nearby text: list any verified alignment or fitting steps shown. Check: the written instructions explain every necessary action.”

This worksheet helps organize the writing; it is not a technical accessibility certification. The cited guidance covers web images and text alternatives, and does not establish whether a particular page or product meets accessibility requirements. [S1] [S2]