How to Write Helpful Alt Text for Website Images

Describe image purpose clearly for people using screen readers. This guide breaks the task into practical decisions, so you can improve the result without adding unnecessary tools or confusion.

write alt text becomes easier to apply when the task is divided into clear choices. Use the ideas below as a working framework, then adjust the details to your audience, tools, risks, and available time.

Understand the image role

A clear decision here prevents repeated corrections later. Decide whether the image is informative, functional, decorative, or complex. Read the surrounding text.

• Decide whether the image is informative, functional, decorative, or complex.
• Read the surrounding text.
• Identify what information would be lost without the image.
• Do not describe every visual detail automatically.

Identify what information would be lost without the image. Do not describe every visual detail automatically. Test this with one real example before applying it to every project.

Write for the page context

Keep the process practical and tied to the result you need. Describe the important subject and action. Include text shown in the image when it matters.

• Describe the important subject and action.
• Include text shown in the image when it matters.
• Avoid starting with image of unless needed.
• Keep wording natural.

Avoid starting with image of unless needed. Keep wording natural. Keep an owner and review date so the step remains useful as circumstances change.

Handle decorative images

Small controls at this stage reduce avoidable risk. Use an empty alt attribute when the image adds no information. Do not repeat nearby text.

• Use an empty alt attribute when the image adds no information.
• Do not repeat nearby text.
• Keep decorative icons hidden from assistive technology.
• Test buttons and links separately.

Keep decorative icons hidden from assistive technology. Test buttons and links separately. Remove anything that adds effort without improving quality, safety, or clarity.

Describe charts and complex visuals

The strongest system is one that people can actually follow. Give a short alt summary. Provide the main insight in nearby text.

• Give a short alt summary.
• Provide the main insight in nearby text.
• Add a data table or longer description when necessary.
• Do not force all chart data into one alt attribute.

Add a data table or longer description when necessary. Do not force all chart data into one alt attribute. When an exception appears, record it and improve the process instead of relying on memory.

Review quality

This part matters because it shapes the quality of every later step. Read the page without seeing the image. Check for keyword stuffing.

• Read the page without seeing the image.
• Check for keyword stuffing.
• Confirm language and spelling.
• Update alt text when the image or context changes.

Confirm language and spelling. Update alt text when the image or context changes. Write the decision down so the same issue does not need to be solved again each time.

A practical way to begin

1. Identify image purpose.
2. Describe only important contextual information.
3. Use empty alt text for decorative images.
4. Provide longer explanations for complex visuals.

Complete the first step with a small real example. Record the result, the time required, and any mistakes or questions. That evidence will show whether the process should be simplified, expanded, or replaced.

Common mistakes to avoid

• Assuming the first attempt will work for every situation.
• Using a temporary shortcut as a permanent process.
• Starting with a tool before defining the problem.
• Copying a large organisation’s process without the same needs or resources.
• Skipping privacy, security, accessibility, or permission checks.

Final takeaway

Describe image purpose clearly for people using screen readers. Focus on the smallest useful version, keep responsibility with a person, and review the outcome after real use. A clear and maintainable method is more valuable than a complicated setup that nobody follows.