Images are a key part of how we communicate online. Whether it’s a stunning photo, a chart full of useful data, or a meme that perfectly captures your mood, visuals play a huge role in storytelling and information sharing. But what happens when someone can’t see those images? Enter alternative text, commonly known as alt text—a crucial feature that ensures your content is accessible to all.
What is alternative text?
Alternative text (alt text) is a short written description that you add to an image’s HTML code. It serves two primary purposes:
Accessibility: Alt text helps people who are blind or visually impaired understand the content and purpose of an image. Screen readers, which convert text on a screen into speech, use alt text to describe images to users who can’t see them.
Search Engine Optimization (SEO): Alt text provides additional context to search engines, improving your website’s visibility in search results.
Why should you add alt text to images?
Adding alt text isn’t just a technical best practice—it’s a step toward inclusivity and better communication. Here’s why it matters:
Improves accessibility
Approximately 2.2 billion people globally experience vision impairment, and many of them rely on assistive technologies like screen readers. By providing descriptive alt text, you’re ensuring that everyone, regardless of their ability, can engage with your content.
Supports web accessibility standards
Alt text is a key requirement of the Web Content Accessibility Guidelines (WCAG), an international standard for making websites accessible. Complying with these guidelines isn’t just good practice; it’s often legally required, especially for government websites, educational institutions, and businesses in certain countries.
Enhances user experience
Alt text isn’t just for users with disabilities—it’s also useful when images fail to load due to slow internet connections or technical glitches. Instead of a blank or broken image icon, users will see your descriptive text, helping them understand what was meant to be there.
Boosts SEO
Search engines can’t “see” images the way humans do, but they can read alt text. Including clear and relevant descriptions helps search engines categorize your content more effectively, which can lead to better rankings in search results.
How to write effective alt text
Writing good alt text is an art. You want to be descriptive, concise, and relevant while avoiding redundancy. Here are some tips:
Be descriptive, but concise
Describe the image in a way that conveys its meaning or purpose. For example:
- Instead of: “Image of a cat”
- Try: “Orange tabby cat lounging on a windowsill, looking outside at birds.”
Avoid repetition
Don’t include phrases like “Image of” or “Picture of.” Screen readers already announce that it’s an image.
Focus on function
Consider why the image is there. Is it decorative, informative, or functional? For example:
- For a graph, describe the key data points: “Bar graph showing sales growth from 2020 to 2023, with a 15% increase in revenue.”
- For decorative images that don’t add meaning, use a null alt text (alt=””), so screen readers skip over it.
Include keywords, but don’t stuff
Incorporating keywords can improve SEO, but make sure they fit naturally into the description. Search engines like Google rely on alt text to understand the context of an image, making it an effective tool for helping your content rank higher in search results. However, there’s a delicate balance between using keywords effectively and going overboard—keyword stuffing can hurt both your SEO and user experience.
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