Write alt text for the image described below. The goal is to give a screen-reader user the information the image contributes in this context, not to reproduce every visible detail. Image description or attached image: [IMAGE] Where it appears and surrounding text: [PAGE CONTEXT] Purpose of the image: [IMAGE PURPOSE] Essential visible text, data, or labels: [ESSENTIAL CONTENT] Platform limits and audience: [PLATFORM REQUIREMENTS]
Ask up to 3 clarifying questions only if the image, its purpose, or its surrounding context is missing. Then provide: 1. Recommended alt text, within the platform limit. 2. A shorter alternative under 125 characters. 3. A note identifying any information that belongs in nearby body text, a caption, or a linked data table rather than alt text. For an informative image, lead with the meaningful subject, action, or takeaway. For a chart, state the trend or comparison and the key values necessary to understand the point; recommend a data table for full values. For a functional image, describe the action or destination, not its appearance. For a decorative image, recommend empty alt text. Include visible words only when they matter and do not repeat text already supplied adjacent to the image. Do not begin with “image of,” guess identities, emotions, locations, diagnoses, or demographic attributes, or claim visual details I did not provide. Before answering, check that the alt text conveys the image’s purpose in context and avoids redundant, subjective, or unsupported details.
Fill in
| Placeholder | What to enter | Example |
|---|---|---|
| [IMAGE] | Attach the image or describe its visible subjects, layout, and relevant details. | Photo of a pharmacist in a white coat handing a small paper bag across a counter to a customer. |
| [PAGE CONTEXT] | Explain where the image appears and summarize the text immediately around it. | Article section explains how to collect a prescription after an online refill. |
| [IMAGE PURPOSE] | State whether the image is informative, functional, decorative, or a chart or diagram. | Informative supporting image. |
| [ESSENTIAL CONTENT] | List meaningful visible words, labels, figures, or data points that must be conveyed. | No visible text needs to be conveyed. |
| [PLATFORM REQUIREMENTS] | Name the platform, any character limit, and the intended audience. | Health-system website; aim for 125 characters or fewer. |
How to use
- Attach the actual image when possible and say what the image is meant to contribute.
- Paste the nearby heading or caption so the model can avoid repeating it.
- For charts, compare the proposed text against the underlying data table.
- Follow up with: “Revise this for a decorative image and tell me whether empty alt is appropriate.”
Variations
Chart alt text
Use for a data visualization with a clear takeaway.
Write alt text for this chart: [CHART DESCRIPTION]. It appears beside [SURROUNDING COPY] and should communicate [MAIN TAKEAWAY]. Key data are [KEY VALUES]. Produce alt text under [CHARACTER LIMIT] characters, then a one-sentence long description and a recommendation for presenting the full dataset. Do not list every value in alt text, infer causes, or omit the period, unit, and comparison group.
Product image
Use for an ecommerce image where the product details matter.
Create alt text for [PRODUCT IMAGE] on a [PRODUCT PAGE]. The useful details are [VISIBLE PRODUCT FEATURES], and the product name is [PRODUCT NAME]. Write one alt-text option under 150 characters that identifies the product and visible distinguishing features without repeating the product title word for word. Do not claim materials, dimensions, color names, or included accessories unless they are visibly confirmed or supplied.
Diagram description
Use for a process, technical, or educational diagram.
Write accessible text for a diagram showing [DIAGRAM SUBJECT]. Its teaching purpose is [LEARNING GOAL], and its labels and sequence are [KEY LABELS AND STEPS]. Provide concise alt text under 180 characters plus a structured long description that preserves the order, connections, and critical labels. Do not claim the diagram is to scale or infer relationships not represented. Flag any detail that should also exist in the main text.
Tips
- The same photo can need different alt text on a news story, a product page, and a decorative hero section because its purpose changes.
- Do not cram every visual detail into alt text; preserve the information a sighted reader gains from the image’s role.
- A chart’s full data should be available in text or a table when the values are necessary for understanding or reuse.
- Empty alt text is appropriate for decoration, but never use it to hide meaningful information from screen-reader users.
FAQ
How long should alt text be?
There is no universal limit, but concise text is usually easier to use. Put complex detail in a nearby description or linked table.
Can AI create alt text from an image alone?
It can propose a draft, but page context and image purpose are necessary to decide what information matters.
Should I include text shown in the image?
Include it when it provides information not already available nearby. Avoid repeating a visible caption verbatim.