How Alt Text Impacts Your Website in 2025
Using consistent alt tags isn’t just an SEO tactic; they have been a part of website coding for as long as the web has been around. They are an important part of accessibility and they affect your online presence – even if you never see them.
Alt tags are HTML attributes that describe images on a website. This provides screen readers a way to tell visually impaired users what images are on a page. They also tell search crawlers whether the images on a page are relevant to a search or keyword.
In this article, we’ll explain the parts of an alt tag, how accessibility requirements might actually help your website, and how best to make sure you’ve got all your bases (or tags) covered.
Attributes of the Mighty Alt Tag
You may see people use these terms interchangeably:
- Alt attribute
- Alt text
- Image caption
But these don’t mean quite the same thing – the first two are parts of the alt tag. To put it in layman’s terms, the “alt attribute” is the box that holds the “alt text”. Ideally, the alt text inside your <img> tags should accurately describe your image for accessibility and SEO.
The image captions are a completely separate piece of code that shows up when a user hovers the mouse over an image. They aren’t going to contribute to your website’s search visibility the same way as tags or file names could, but they are positive for user experience and engagement.
Accessibility Over Keywords
Each year, thousands of accessibility lawsuits are filed for a lack of ADA website compliance. One way that the Americans with Disabilities Act (ADA) addresses this concern is in Title II and it sets WCAG 2.1 or 2.2 Level AA as the standard for evaluating whether ADA requirements for websites are being met.
Imagine the last time you went searching for a product you needed via web search or online store. Thousands of pictures, product images, or videos are likely showing up as results. It’s a breeze to scroll through and visually scan for what you want.
Now imagine doing that without the pictures.
Web users with visual impairments rely heavily on the devices they use (screen readers, etc) to read or otherwise interpret the information on a page. If you set up a website without alt tags, they aren’t going to know what you’re showing them.
One exception to this rule is when an image is purely descriptive and it’s content is already described in surrounding text. Another might be an image that doesn’t add any meaningful information to the page. In these cases, it’s okay to use an empty alt attribute.
Alt Tags and SEO
Don’t be discouraged by all these requirements for accessibility compliance – there’s a silver lining here! Accurately describing your site’s images for accessibility also gives us opportunities to add keywords.
If your website or page is about penguins, for example, it would make sense to use a photo of a penguin. If you’re accurately describing the photo in the alt text, of course you would use the word “penguin” and potentially even describe what the penguin is doing. All of this strengthens your website in search queries for penguin-related topics.
Not all alt text is created equal, however. It’s important that you don’t just stuff in keywords or use a vague term like “image of a penguin”. Remember these will be read aloud for some users, and that AI search is conversational and friendly. Make your alt text relevant, accurate, and don’t forget that if there’s text in the image – you need to transcribe that as well.
Practical and Pretty Important
Accurate alt attributes for your website images serve both a practical end (SEO) and an important mission (accessibility). They are also an important piece of maintaining ADA compliance, and protecting yourself from lawsuits.
There are some free tools online that can scan your website for SEO opportunities or improvements – but most of them will involve a trial subscription or require signing in. If you’re intimidated by this, or just too busy, it may be better to find a trusted SEO professional who can help.
Now more than ever, alt tags will be important for your website. AI-generated content, voice-assisted browsing, and stricter accessibility enforcement are still changing the landscape of search. The descriptive text used in these humble little tags can inform individual users, web crawlers, and voice-based searches from home AI devices as well. Use them well and consistently; they will serve your website with more traffic and ensure that all web users can browse your content and engage with it.
