Alt text is one of the most overlooked parts of a website, yet it plays a very important role in accessibility, search engine optimization, and overall user experience. Many beginners either ignore alt text completely or use it incorrectly by stuffing keywords or leaving it empty. When used properly, alt text helps both people and search engines understand images better.
In this guide, you will learn what alt text is, why it matters, and how to use it correctly in a simple and practical way. This article is written to stay relevant for years and can be applied to any website, blog, or web project.
What Is Alt Text?
Alt text, short for “alternative text,” is a written description added to an image in HTML. It is used to describe what an image shows when the image cannot be displayed or when a user relies on assistive technology.
In simple terms, alt text answers the question:
“If someone cannot see this image, what should they know about it?”
Alt text is read aloud by screen readers for visually impaired users. It is also used by search engines to understand the content of an image since search engines cannot see images the way humans do.
Alt text is added inside the <img> tag in HTML using the alt attribute. Even if you are using WordPress or another CMS, the concept remains the same.
Why Alt Text Is Important
Alt text serves multiple purposes at the same time, which is why it is so important to use it properly.
First, alt text improves accessibility. People who use screen readers depend on alt text to understand images. Without it, important information can be completely lost for them.
Second, alt text helps with SEO. Search engines use alt text to understand image content, which can help your images appear in image search results and support the relevance of your page.
Third, alt text improves usability. When an image fails to load due to slow internet or technical issues, the alt text appears in its place, helping users understand what was supposed to be there.
Alt text is not just a technical detail. It is part of creating a better and more inclusive web.
When You Should Use Alt Text
In most cases, every meaningful image on your website should have alt text. This includes:
- Blog images
- Featured images
- Product images
- Infographics
- Icons that convey meaning
If an image adds value or information, it needs proper alt text.
However, not all images need descriptive alt text. Decorative images that do not add meaning can have empty alt text so they are ignored by screen readers.
Understanding the difference between meaningful and decorative images is key to using alt text properly.
How to Write Good Alt Text
Good alt text is clear, accurate, and useful. It should describe the image in a way that makes sense in the context of the page.
A simple approach is to imagine you are describing the image to someone over the phone. You would mention the most important details, not everything.
Good alt text usually:
- Describes what is visible
- Matches the purpose of the image
- Fits naturally into the content
- Is short but informative
There is no fixed length, but most alt text works best when it is concise and focused.
What to Include in Alt Text
When writing alt text, focus on what matters most.
Ask yourself:
- What is the image showing?
- Why is this image on the page?
- What information does it provide?
For example, if the image shows a person working on a laptop, the alt text could describe that action. If the image is a chart or diagram, the alt text should explain what the chart represents.
Context matters. The same image might need different alt text depending on where it is used.
What to Avoid in Alt Text
Many people make mistakes when writing alt text. These mistakes reduce its effectiveness and can even harm accessibility.
Avoid starting alt text with phrases like:
- “Image of”
- “Picture of”
- “Graphic showing”
Screen readers already announce that it is an image, so these phrases are unnecessary.
Avoid keyword stuffing. Alt text is not meant to be a list of keywords. Stuffing keywords makes it sound unnatural and does not help users.
Avoid being vague. Alt text like “image” or “photo” provides no useful information.
Avoid copying captions or file names directly. Alt text should be written intentionally, not automatically.
Alt Text for Decorative Images
Decorative images are images that do not add information or meaning. They are used purely for visual design.
Examples include:
- Background patterns
- Decorative icons
- Divider graphics
For decorative images, the correct approach is to use empty alt text. This tells screen readers to skip the image so users are not distracted by unnecessary descriptions.
Using empty alt text is better than writing meaningless descriptions.
Alt Text for Functional Images
Functional images are images that perform an action or represent a function.
Examples include:
- Buttons with icons
- Icons used as links
- Images used as navigation elements
In these cases, alt text should describe the function, not the appearance.
For example, if an icon opens a menu, the alt text should describe that action rather than how the icon looks.
Alt Text for Complex Images
Some images are more complex, such as charts, graphs, and infographics. These images often contain detailed information that cannot be fully explained in short alt text.
In such cases:
- Use alt text to give a brief summary
- Provide a longer explanation in surrounding text or a caption
Alt text does not need to contain every detail, but it should guide users to where they can find the full explanation.
Alt Text and SEO
Alt text helps search engines understand your images, but it should always be written for humans first.
Using relevant keywords naturally in alt text is fine, as long as it makes sense. If a keyword fits naturally into the description, you can include it. If it feels forced, leave it out.
Alt text works best for SEO when it:
- Matches the image content
- Supports the page topic
- Is written clearly and naturally
Search engines value usefulness more than keyword density.
Alt Text in Content Management Systems
Most content management systems provide a field for alt text when uploading images. It is important to fill this field manually instead of leaving it empty.
Relying on automatic alt text generation is not recommended. Automated descriptions are often inaccurate or too generic.
Taking a few seconds to write proper alt text can greatly improve the quality of your website.
Common Myths About Alt Text
One common myth is that alt text is only for SEO. This is not true. Accessibility is the primary purpose of alt text.
Another myth is that alt text needs to be very long. In reality, shorter and clearer descriptions are usually better.
Some people think decorative images should be removed entirely. Instead, they should simply have empty alt text.
Understanding these myths helps you use alt text correctly.
How Alt Text Improves User Experience
Alt text improves the experience for many users, not just those with disabilities.
Users on slow connections benefit when images fail to load. Users using text-only browsers also rely on alt text.
By writing good alt text, you are making your website more reliable and inclusive.
Alt text is a small detail that makes a big difference. When used properly, it improves accessibility, supports SEO, and enhances user experience. It helps your website communicate clearly with both humans and search engines.
The key to good alt text is intention. Write it to describe the image clearly and honestly, without overthinking or overloading it with keywords. Focus on what matters and why the image exists.
By making alt text a regular part of your content creation process, you create a more professional, accessible, and future-ready website. This habit will continue to benefit your site as web standards evolve and accessibility becomes even more important.