Alt text is essential for making websites accessible to everyone. It not only enhances the user experience but also improves search engine optimization (SEO) and ensures that content is accessible to people with disabilities. Understanding the importance of alt text can significantly benefit both your site’s visibility and inclusivity.
What is alt text?
Alt text, short for alternative text, is a brief description of an image that's embedded in a webpage's HTML code. While it's invisible to most users, it plays a vital role for those using screen readers or browsing with images turned off. Think of it as a verbal snapshot, painting a picture with words for those who can't see the image itself.
Why it matters
- Accessibility:
The World Health Organization reports that over 2.2 billion people worldwide have a visual impairment. For many of these individuals, screen readers are their window to the digital world. Alt text ensures they don't miss out on crucial visual information. - SEO Boost:
Search engines can't "see" images, but they can read alt text. By providing clear, descriptive alt text, you're giving search engines valuable context about your content, potentially improving your site's visibility in search results and image searches. - Enhanced User Experience:
Even for sighted users, alt text can be beneficial. It provides context when images fail to load due to slow connections or when users choose to browse with images disabled to save data. - Legal Compliance:
In many countries, web accessibility is not just good practice—it's the law. Proper use of alt text can help ensure your website meets legal requirements for digital accessibility.
Crafting Effective Alt Text: A How-To Guide
- Be Concise Yet Descriptive:
Aim for brevity without sacrificing important details. Most screen readers cut off alt text after 125 characters. - Context is King:
Tailor your alt text to how the image is used in your content. An image of a cat in an article about pets will need different alt text than the same image used to illustrate a metaphor in a business article. - Avoid Redundancy:
If the image is described adequately in the surrounding text, your alt text can be brief or even empty (using alt=""). - Skip the Obvious:
Don't start with "Image of..." or "Picture of...". Screen readers already announce that it's an image. - Use Keywords Judiciously:
While it's okay to include relevant keywords, avoid keyword stuffing. Natural language always wins.
Here's a before-and-after example to illustrate these principles:
- Before: Image of cat
- After: Ginger tabby cat lounging on a windowsill, bathed in sunlight
Implementing Alt Text: The Technical Side
Adding alt text to your images is straightforward. In HTML, it looks like this:
<img src="image-file-name.jpg" alt="image description">Most content management systems and social media platforms provide fields for adding alt text when you upload images.
When Alt Text Isn't Necessary
While alt text is crucial for most images, there are exceptions:
- Purely decorative images that don't add meaning to the content
- Images that are described fully in the surrounding text
- Repetitive images, like a series of product shots that are essentially the same
In these cases, use an empty alt attribute (alt="") to signal to screen readers that they can skip the image.
Further reading on Alt text
- Everything you need to know to write effective alt text (Microsoft)
- Alternative Text (WebAIM)
- HTML <img> alt Attribute (W3schools)
The Bottom Line
Alt text is a powerful tool for inclusivity. By taking a few moments to add thoughtful alt text to your images, you're not just improving your SEO—you're opening up your content to a wider audience and creating a more accessible web for everyone.
Remember, the web is for everyone. Let's make sure everyone can experience it fully.
Take a moment today to review the images on your website. Are they all equipped with descriptive alt text? If not, it's time to make a change. Your future visitors—and search engines—will thank you.
