Alt text might be behind the scenes, but it plays a front-and-center role in making your website more inclusive, user-friendly and search-engine smart

CREDIT: This is an edited version of an article that originally appeared in SEO.com

Alt text – short for “alternative text” – is a written description of an image that serves multiple important purposes. Whether you’re adding new images to your website or managing content, knowing how to write effective alt text is essential for improving accessibility, enhancing user experience and boosting your SEO performance.

What Is Alt Text?

Alt text is the descriptive copy embedded in an image’s HTML tag. It’s primarily used by screen readers to describe images aloud to users with visual impairments, allowing them to better understand the visual elements of a webpage. But alt text isn’t just for accessibility. It also plays a role in SEO. Search engines can’t see images, so they rely on alt text to interpret and index image content correctly.

Why Is Alt Text Important?

Alt text is a cornerstone of accessible web design. It ensures that users who rely on assistive technology, such as screen readers, can access and understand the images on your site. Descriptive alt text bridges the gap between visual and non-visual experiences.

Even for users without impairments, alt text improves the browsing experience. For instance, if images fail to load due to slow internet connections, alt text gives users a sense of what the image was meant to convey – avoiding blank spaces and confusion.

Alt text also plays a key role in image SEO. Search engines like Google can’t “see” your images, but they can read your alt text. Properly optimised alt text can improve your visibility in search engine results pages (SERPs) and may even help your images appear in Google Image Search, making your content more discoverable and clickable.

How to Write Effective Alt Text

Crafting strong alt text takes a bit more thought than simply describing the image. Here are some best practices:

Be Specific and Concise

Describe exactly what’s in the image in a few words or a short sentence. Aim to communicate the purpose or meaning of the image, not just the objects within it.

Example:
Instead of: “Storage box”
Use: “Clear storage box with easy grip foam handles used for transporting files”

Provide Context

Alt text should support the surrounding content. If an image is illustrating a concept discussed in the text, reference that context in your description.

Example:
For an image in an article about remote work:
“Person working on a laptop in a home office setup with plants and natural light.”

Avoid Keyword Stuffing

While it’s good to include relevant keywords naturally, don’t overload your alt text with keywords. This can hurt both accessibility and SEO.

Bad Example: “Office, office desk, home office, working from home, laptop on office desk.”
Better: “Modern home office desk with a laptop, coffee cup and notepad.”

When You Don’t Need Alt Text

Not every image on your website needs a description. Decorative images – like background graphics or stylistic flourishes that don’t convey meaningful content – can use empty alt attributes (alt=””). This tells screen readers to skip them, reducing unnecessary noise for users.

When used correctly, alt text isn’t just a box to tick – it’s a powerful tool that makes your website more inclusive, user-friendly and SEO-ready. By writing clear, purposeful descriptions and understanding when and how to use them, you’re not just helping your site rank better – you’re making it more welcoming for everyone.