Ensuring Inclusive and Accessible Content: Effective Use of ALT Text and Descriptive Elements in Images

Images carry information. A chart shows a trend, a photograph shows who took part in an event, and an infographic explains a process. Blind People and People with Low Vision who read with a screen reader or a Braille display receive that information only when the page supplies it as text.

This article explains how to supply it with alt text, captions, titles, and extended descriptions, following Best Practices and the International Accessibility Standards. As Bahá’ís, we hold up Unity in Diversity and respect how each person self-identifies. A careful image description is one practical way to act on both.

Access to Information Is a Right

The Web Content Accessibility Guidelines (WCAG) 2.2, a World Wide Web Consortium (W3C) Recommendation published on 12 December 2024, address images in Success Criterion 1.1.1, a Level A requirement. It calls for content that is not text to have “a text alternative that serves the equivalent purpose.” W3C explains that text alternatives can be “rendered through any sensory modality,” whether visual, auditory, or tactile. One well written description therefore reaches a reader through speech or through a Braille display.

Many pages do not meet this requirement. The 2026 WebAIM Million analysis of the top one million home pages, with results from February 2026, found that 16.2% of all home page images, an average of 10.8 per page, had missing alternative text.

The Universal House of Justice places access to knowledge among the rights of every human being:

“Access to knowledge is the right of every human being, and participation in its generation, application and diffusion a responsibility that all must shoulder in the great enterprise of building a prosperous world civilization—each individual according to his or her talents and abilities. Justice demands universal participation.” -The Universal House of Justice, Riḍván 2010 – To the Bahá’ís of the World

The Social Model of Disability locates the barrier in the page and not in the reader. An image with no text alternative is a communication barrier created by its publisher, and removing it is a shared responsibility. It is service, not a favor done at our convenience, as the discussion of charity versus service explains.

Anyone who publishes or distributes information to the community is responsible for making sure it is accessible. This holds for a newsletter, a website, a slide deck, an email, or a social post. A designer, a volunteer, or a committee may prepare the material, but the responsibility stays with the publisher, because a reader cannot add a description that is missing.

Descriptive Elements in Images

Alt Text

Alt text is the value of the alt attribute on an image. WCAG Technique H37 calls for a short text alternative that must “convey the same meaning as the image,” which is not always a literal account of how the image looks. When an image contains words that are important to understanding the content, the alt text includes those words. The guide to writing meaningful, descriptive alt text shows how to apply this to book covers, logos, and photographs of people.

The W3C images tutorial gives the test: “The alt text should be the most concise description possible of the image’s purpose.” It adds that alt text usually does not include words such as “image,” “icon,” or “picture.” State the reason the image was included, and describe what a Blind reader must know to share that purpose.

For example, alt="A smiling Black man holds a framed award at a wooden podium." names the person, the action, and the setting in one sentence.

Captions

A caption is visible text beside the image. It supplies what the picture cannot show by itself: names, the event, the date, the significance, and attribution. For example, <figcaption>James Johnson accepts the 2024 Annual Achievement Award.</figcaption> names the person and the occasion.

A screen reader reads the caption as well, so a Blind reader hears both texts in sequence. Keep the roles separate. The alt text carries what the image shows, and the caption carries the names and context. W3C advises that an image whose content is already present as real text nearby can take an empty alt attribute. When the caption adds context the image does not give, repeating it in the alt text only makes the reader hear the same sentences twice.

Titles

Titles identify and number images, particularly in long documents. For example, Figure 1: Visitor numbers to the Green Trees main walk, 2008 to 2019 lets every reader find and refer to a specific image. A title organizes content and does not describe people.

Extended Descriptions

Some images hold more information than a short phrase or sentence can carry, such as charts, diagrams, maps, and infographics. W3C calls these complex images and requires a two part text alternative: a short description that identifies the image, and a long description that carries the full information. W3C lists several ways to attach the long description, including a link next to the image and a description placed directly beside it.

The infographic at the top of this page uses a native HTML details element labeled “Show/Hide Description,” placed directly after the image. Readers who want the full description open it. Labeled paragraphs inside it keep the description easy to scan by keyboard or by screen reader.

Calling an Informative Image Decorative Removes It for Blind People

W3C’s decision tree starts with one question: “Does the image contribute meaning to the current page or context?” When the answer is yes, the image is informative and takes a brief description in the alt attribute. An empty alt="" is correct only for an image that is purely decorative.

Marking an informative image as decorative takes it away from Blind readers while sighted readers keep it. This is a barrier created by a decision, and it excludes People with Disabilities from content presented to other readers. The decision belongs to the author, and it rests on the reason the image is on the page. If the answer is to exclude it, reflect on why it is there for the readers who can see it.

Treat each image as a content decision about who receives its meaning.

Types of Images and Appropriate Descriptions

Decorative Images

Decorative images do not add information to the page. They take a null, or empty, alt="" so that access technology such as a screen reader can skip them. Leaving out the alt attribute is not an option, because some screen readers then announce the file name of the image instead.

Examples of decorative images:

• Visual styling such as borders, spacers, and corners.
• Images that improve the appearance of a link or enlarge its clickable area without adding information.
• Images that illustrate adjacent text without contributing information.
• Images that the surrounding text already identifies and describes.

Informative Images

Informative images convey a simple concept or piece of information that a short phrase or sentence can express. The text alternative conveys the meaning of the image, which typically is not a literal description of it.

Examples of informative images:

• An icon that labels a telephone or fax number.
• An image that adds to the information in the text.
• A diagram that illustrates a concept or a process.
• An icon that shows a file format.

Functional Images

Functional images start an action instead of conveying information. They appear in buttons, links, and other controls. The text alternative states the action that will happen and not the picture: “print this page” instead of a printer, and “search” instead of a magnifying lens.

Examples of functional images:

• A linked logo. Name the organization and the destination, as in “Example.com homepage” and not “Example.com logo.”
• An icon in a button or beside link text that represents an action such as printing, searching, or opening a window.

Complex Images

Complex images hold substantial information, more than a short phrase can express. Give them a short alt text that identifies the image and a long description that carries the data, the relationships, and the conclusions the image shows. Every number and label that matters to understanding the image belongs in the description.

Describing People with Respect

When an image shows people, the description honors Unity in Diversity by naming what a reader would take in at a glance, in plain and respectful words:

• Describe the people, what they are doing, and where. Leave out clothing and other peripheral detail.
• Name race with group terms, gender by visible presentation, and age only when the source confirms it or the age is unmistakable.
• Include disability related detail, such as a white cane, a wheelchair, or sign language, when it is part of why the image is there and the source confirms it.
• Use the words people have shared about how they identify.
• Put names in the caption and not in the alt text.

Choose language that respects the readers the description is for. Blind or Low Vision is the preferred wording.

Putting It into Practice

Each element serves a specific group and removes a specific barrier:

• Alt text gives Blind People and People with Low Vision who use a screen reader or Braille display the meaning of each informative image.
• Long descriptions give the same readers the full content of charts, diagrams, and infographics.
• Captions give every reader the names and context, and screen reader users hear them in sequence with the image.
• Titles let readers find and refer to a specific figure.
• Descriptions of functional images tell keyboard and screen reader users what a control does.

Build these steps into planning from the start through inclusive design, so no image goes out as a promise for later. The work of removing barriers is finished when the person who faced the barrier can use the result.

Also see:

• W3C Web Accessibility Initiative Images Tutorial
• Understanding Success Criterion 1.1.1 on text alternatives
• WCAG Technique G94, a short text alternative that serves the same purpose as the image

Reflection Questions for Community Builders

1. Think of the images in our newsletters, websites, slide decks, social posts, and flyers over the past year. Which carry an alt text or a long description, and who listened to them with a screen reader?
2. For each image we publish, who decides whether it is informative or decorative, what evidence do they use, and have Blind People in our community reviewed those decisions?
3. Where do our captions repeat the alt text, and where do they supply names, dates, and context that a Blind reader has no other way to learn?
4. Which of our flyers, charts, and infographics contain words, and does every word reach a Blind reader through a short alt text, a long description, or the nearby text?
5. When we describe people in photographs, whose words do we use to name how they identify, and who confirmed the description with the person pictured?
6. When an image goes out with no description, who notices, how does a Blind member report it, and what happens in the days that follow?