Images play a major role in making websites visually appealing and engaging. They help explain concepts, showcase products, and create a better user experience. However, when images are published without alternative text, also known as alt text, they can create significant accessibility barriers for users who rely on screen readers and other assistive technologies.
Missing alt text is one of the most common accessibility issues found on websites. Fortunately, it is also one of the easiest problems to identify and fix. Understanding how to add meaningful alt text can improve accessibility, support compliance efforts, and enhance the overall usability of your website.
What Is Alt Text?
Alt text, short for alternative text, is a written description added to an image within a webpage's HTML code. Screen readers use this text to describe images to users who are blind or have low vision. Alt text also appears when an image fails to load, giving users context about what should have been displayed.
For example, if a website includes an image of a golden retriever playing in a park, the alt text might read:
"Golden retriever running across a grassy park."
This description helps users understand the content and purpose of the image even if they cannot see it.
Why Missing Alt Text Is a Problem
When an image lacks alt text, screen readers may either skip the image entirely or announce it in an unhelpful way. Users can miss important information, instructions, or context that sighted visitors can easily access.
Missing alt text can create several issues:
- Reduced accessibility for people with visual impairments
- Poor user experience for screen reader users
- Potential noncompliance with accessibility standards
- Lost context when images fail to load
- Missed opportunities for search engine optimization
How to Identify Missing Alt Text
Before fixing the issue, you need to find where it exists on your website.
Use Accessibility Testing Tools
Many accessibility auditing tools can automatically detect images that are missing alt attributes. Popular tools include browser extensions, widgets, website scanners, and accessibility evaluation platforms. These tools can quickly generate reports highlighting images that need attention. For example, the Webmax widget catches all the detailed issues of an image on your website and provides you with all the missing alternative texts. This widget is very easy to use for any website owner; you don’t have to be tech-savvy to use it.
Review Website Content Manually
Automated tools are useful, but manual review is equally important. Go through your pages and inspect images individually. Consider whether each image serves a purpose and whether its current description accurately communicates that purpose.
Check Your Content Management System
Many content management systems provide image libraries where alt text can be added directly. Reviewing these libraries can help you identify images that have empty or missing descriptions.
Determine the Purpose of Each Image
Not every image requires the same type of alt text. The first step in fixing missing alt text is understanding why the image exists.
Informative Images
Informative images convey meaningful content that supports the page's message. These images should include descriptive alt text that explains the information being presented.
Example:
Alt text: "Customer service representative assisting a client over the phone."
Functional Images
Functional images act as buttons, links, or controls. The alt text should describe the function rather than the visual appearance.
Example:
Alt text: "Search" for a magnifying glass icon that opens a search feature.
Decorative Images
Decorative images do not add meaningful information and are used only for visual design purposes. These images should typically have empty alt text so screen readers can ignore them.
Example:
alt=""
This approach prevents unnecessary distractions for users relying on assistive technology.
Complex Images
Charts, graphs, diagrams, and infographics often contain detailed information that cannot be fully explained in a short alt text description.
In these cases, provide a concise alt text summary and include a more detailed explanation elsewhere on the page.
Write Effective Alt Text
Once you understand the image's purpose, you can create meaningful descriptions.
Be Specific
Provide enough detail to communicate the image's purpose without being overly lengthy.
Instead of:
"Dog"
Use:
"Brown Labrador retrieving a tennis ball."
Focus on Context
The same image may require different alt text depending on its context.
For example, a photo of a laptop on a product page might use:
"15-inch silver laptop with touchscreen display."
The same image in a blog post about remote work might use:
"Professional working remotely using a laptop."
The context determines what information is most important.
Avoid Redundant Phrases
Screen readers already identify images as images. There is usually no need to begin alt text with phrases such as:
- "Image of"
- "Picture of"
- "Photo of"
Instead, go directly into the description.
Keep It Concise
Most alt text should be brief and focused. Aim to communicate the essential information without writing a full paragraph. A clear sentence or short phrase is often sufficient.
Add Alt Text to Your Website
The exact process depends on your platform, but the general principle remains the same.
In HTML, alt text is added using the alt attribute:
<img src="dog.jpg" alt="Golden retriever running through a park">
For websites built with content management systems, there is usually a designated field where you can enter the alt text when uploading or editing images. Be sure to save your changes and verify that the descriptions appear correctly.
Test Your Changes
After adding alt text, test your website to ensure the updates work as intended.
Use a Screen Reader
Listening to your content through a screen reader provides valuable insight into the user experience. It can help you identify descriptions that are unclear, repetitive, or missing important context.
Run Another Accessibility Scan
After making updates, rerun your accessibility testing tools to confirm that missing alt text issues have been resolved. This step helps ensure that no images were overlooked during the remediation process.
Review New Content Processes
Fixing existing images is only part of the solution. Establish workflows that require alternative text (alt text) whenever new images are uploaded. This helps prevent accessibility issues from returning in the future.
Common Alt Text Mistakes to Avoid
While adding alt text, watch out for common errors:
- Leaving alt attributes completely missing
- Using file names as descriptions
- Writing vague descriptions such as "image" or "graphic"
- Stuffing alt text with keywords for SEO purposes
- Providing lengthy descriptions that overwhelm users
- Adding descriptions to purely decorative images
Avoiding these mistakes helps create a smoother experience for assistive technology users.
Ending Note from Webmax
Fixing missing alt text on images is one of the simplest and most effective ways to improve website accessibility. Proper alt text ensures that users who rely on screen readers can understand visual content and interact with your website more effectively.
By identifying missing descriptions, understanding the purpose of each image, writing meaningful alt text, and testing your updates, you can create a more inclusive digital experience for all visitors. The Webmax scanner widget will help you to identify and solve all these issues. Accessibility is not just about compliance. It is about ensuring that everyone has equal access to the information and services your website provides.