How to Make Images Accessible and Write Effective Alt Text
Images must be accessible to users who rely on screen readers or who have images disabled. Under the updated federal Title II digital accessibility standards effective April 2026, all meaningful images on public-facing webpages are required to include appropriate alternative text, commonly referred to as alt text.
Alt text exists to communicate the meaning, purpose, or function of an image to users who cannot see it. It should not be used as decorative copy embellishment, a caption, or an SEO field. Alt text is functional content that ensures equal access to information.
When is alt text required?
Alt text is required for any image that conveys information, supports understanding of the page content, functions as a link or button, or contains text that is not otherwise available on the page.
Decorative images that do not add meaning, such as background textures, visual dividers, or purely aesthetic graphics, should use empty alt text (alt="") so screen readers can skip them without adding noise.
How to write useful alt text
Effective alt text is concise, descriptive, and written in context. It should describe what the image communicates, not simply what it looks like. A good rule of thumb is to ask: If this image were removed, what information would the user be missing?
Alt text should be written in plain language and reflect the intent of the surrounding content. Screen reader users already have access to the page text, so alt text should not repeat nearby headings or paragraphs verbatim. Instead, it should complement them by filling in the missing visual information.
Recommended length
Alt text should generally be short and efficient. An ideal length is between 5 and 15 words, with an upper limit of approximately 125 characters, which aligns with common screen reader behavior. If an image requires a long explanation to make sense, that explanation likely belongs in the page content rather than the alt text.
What to avoid when writing alt text
Alt text should not begin with phrases such as “image of,” “picture of,” or “graphic of,” as screen readers already announce the element type. File names, keyword-stuffed descriptions, and overly visual details that do not contribute meaning should also be avoided.
Alt text should never be used as a substitute for captions, design notes, or instructional text that belongs elsewhere on the page.
How to handle images that contain text (flyers, posters, graphics)
Images that contain text, such as flyers, posters, or promotional graphics, require special care. Text embedded in images is not accessible by default and must be provided in an alternative format.
The preferred approach is to avoid using images to convey essential text whenever possible and instead present the information as real HTML text on the page. If the image must be used, the full text content should be provided elsewhere on the page in a readable format. In these cases, alt text should briefly describe the purpose of the image rather than attempting to transcribe all visible text.
If the image’s primary purpose is the text itself and no HTML version exists, the
full text must be included immediately adjacent to the image. The alt text should
remain short and direct users to the nearby content.
Example
A department has a promotional flyer image for a campus event titled “Spring Research Symposium – April 18, 1–4 PM, Student Activities Center.” The flyer includes the event title, date, time, location, speaker names, and registration details.
Preferred (best) approach:
Instead of relying on the flyer image to communicate the details, the page includes the event information as real HTML text:
- Event title as a heading
- Date, time, and location in paragraph or list form
- Registration link as a standard text link
The images included are photos from the original flyer taken off of the flyer and displayed on their own.
Alt text:
“John Doe standing at podium from previous symposium”
This works because all essential information is available on the page in accessible text.
If the image must be used and contains important text
The flyer image remains on the page, but the full event details are written out directly below it in HTML text. The alt text still stays short and descriptive, summarizing the image rather than repeating its contents.
Alt text:
“Promotional flyer for the Spring Research Symposium”
Linked images
When an image functions as a link, the alt text must describe the action or destination, not the visual appearance of the image. Users should understand what will happen when the image is activated, just as they would with a text link.
Using images in Modern Campus CMS
When adding images in Modern Campus, the Alt Text field should always be reviewed and intentionally completed. Captions or surrounding text do not replace alt text, and decorative images should be clearly marked with empty alt text. Alt text should be treated as part of the content itself and reviewed with the same care as written copy.
How Alt Text Affects Accessibility
Under the Title II accessibility standards effective in 2026, improper or missing alt text may result in accessibility compliance failures. These requirements apply to all public-facing content, including archived pages and low-traffic sections of the site.
Accessible images ensure that all users can fully understand and interact with web content. Writing thoughtful alt text is a small effort that delivers a significant impact on usability, compliance, and overall content quality.