Alt Tags

Homepage Glossary Alt Tags

Alt tags are an important element for both SEO and web accessibility, helping search engines and users understand the content of images on a website. Let’s explore what alt tags are, why they’re needed, and how to use them correctly.

What are Alt Tags

An alt tag (alternative text) is an HTML attribute used to describe the content of an image on a webpage. It is displayed if the image fails to load and helps search engines understand what the picture contains.

Example of HTML image code with an alt tag:

html

Why Alt Tags are Important

SEO Optimization. Search engines cannot “see” an image like a human can, but they analyze the alt tag to understand the image’s content and determine its relevance to the page’s keywords.
Accessibility. Alt tags assist people with disabilities who use screen readers to understand what is depicted in the image.
Fallback for Errors. If an image fails to load, the browser displays the alt tag text in its place.
Image Search. Proper alt tags help images appear in search results for images (Google Images, Yandex.Images).

How to Write Alt Tags Correctly

Describe the Image. The text should accurately reflect what is depicted in the image.
Use Keywords. You can include relevant keywords, but don’t overload the text. It should remain natural and informative.
Be Concise. The optimal length for an alt tag is 5-15 words. Excessively long text reduces readability and effectiveness.
Ensure Uniqueness. Each alt tag on a page should be unique, especially if there are many images.
Don’t Use Empty Tags Unnecessarily. An empty alt=”” is only acceptable for purely decorative images that carry no semantic meaning.

Examples of Alt Tags

For an Online Store

Product image: <img src=”red-shoes.jpg” alt=”Red Nike sneakers for women”>
Promotional banner: <img src=”sale-banner.jpg” alt=”20% discount on all sneakers at the online store”>

For a Blog

Article image: <img src=”seo-tips.jpg” alt=”Tips for SEO website promotion”>
Infographic: <img src=”marketing-funnel.jpg” alt=”Sales funnel: stages from lead to customer”>

For Decorative Elements

If the image is decorative and has no semantic value: <img src=”decor.jpg” alt=””>

Common Mistakes with Alt Tags

Missing Alt Tags. If alt tags are omitted, search engines cannot understand the image’s content, harming SEO.
Keyword Stuffing. Don’t cram too many keywords into an alt tag—it reduces naturalness and may be flagged as spam.
Vague Descriptions. Descriptions like alt=”picture” or alt=”photo” provide no useful information about the content.
Duplicate Alt Tags. Each tag should be unique to allow search engines and users to differentiate between images.

Conclusion

Alt tags are an essential element for SEO and website accessibility. They help search engines understand image content, improve indexing, and increase the chances of images appearing in search results. Correct and unique alt tags enhance the website experience for all users while simultaneously boosting SEO effectiveness.