Understanding Alt Text
Alt Text, short for "alternative text," is a brief description added to the HTML code of an image on a website. This description is not visible on the page under normal conditions. But it serves two important purposes. First, it helps people who use screen readers—software that reads web content aloud—understand what the image shows. Without Alt Text, someone who can't see the image would miss important information. Second, search engines like Google use Alt Text to understand the content of images, which can help the page rank better in search results.
Alt Text should be written in plain language and focus on the key details of the image. For example, if the image shows a red bicycle parked on a sidewalk, the Alt Text might say "red bicycle parked on a sidewalk." It doesn't need to be a full sentence. But it should be clear and accurate. Avoid stuffing keywords into Alt Text, as this can make it harder for screen readers to understand and may hurt SEO.
How Alt Text Works?
Alt Text is added to an image using the "alt" attribute in the HTML <img> tag. The basic structure looks like this: <img src="image.jpg" alt="description of the image">. When a browser loads the page, it reads this code and knows to display the image. If the image cannot load—due to a slow internet connection or a broken file - the browser will show the Alt Text instead. Screen readers also read this Alt Text aloud to describe the image to users who cannot see it.
Search engines use Alt Text to understand what an image is about, just like they use the text on a page. This helps them decide when to show the image in search results, such as in Google Images. For example, if someone searches for "red bicycle," a page with an image of a red bicycle and good Alt Text is more likely to appear in the results. But Alt Text is not a place to stuff keywords. It should describe the image naturally and accurately.
Why Alt Text Matters?
Alt Text is important for accessibility because it ensures that people with visual impairments can understand the content of images. Without Alt Text, screen readers may only read the file name, which is often unhelpful, like "IMG_1234.jpg." This can make it difficult for users to fully engage with the content. And many countries have laws requiring websites to be accessible. And missing Alt Text can lead to compliance issues.
For SEO, Alt Text helps search engines understand the context of images, which can improve the page’s ranking. Images with good Alt Text are more likely to appear in image search results, bringing more visitors to the site. Alt Text also supports other SEO efforts, such as keyword relevance. But it should never be used to spam keywords. The primary goal is to describe the image clearly and accurately.
When Alt Text Matters Most?
Alt Text is especially important for images that convey important information, such as charts, infographics. Or product photos. For example, if a blog post includes a graph showing sales data, the Alt Text should describe the key takeaways of the graph, not just say "graph." Similarly, product images on an e-commerce site should include Alt Text that describes the product’s color, size. Or other important details. This helps both search engines and users understand what is being sold.
Alt Text is less critical for decorative images that don't add meaning to the content, such as background images or dividers. In these cases, it's acceptable to use empty Alt Text (alt="") to tell screen readers to skip the image. But it is always better to include Alt Text for images that contribute to the content, even if they seem minor. Every image is an opportunity to improve accessibility and SEO.
