Definition
What is Alt Text?
Alt text, short for alternative text, is a descriptive text added to an image’s HTML code that provides a textual alternative for visually impaired users or when the image fails to load. It describes the appearance or function of an image on a web page, ensuring that all users can understand the content and context of the image.
How It Works
Function and Concept
Alt text is implemented through the alt attribute in an image’s HTML code, such as <img src="image-file-example.jpg" alt="Alt text goes here">. This text is read aloud by screen readers for users with visual impairments, allowing them to understand the content and purpose of the image.
Alt text is displayed in place of an image if the image file cannot load, enhancing user experience by providing a description of the missing content. Search engine bots use alt text to understand the content and context of images, which helps in indexing and ranking images in image search results.
Practical Use Cases
Accessibility
Alt text is crucial for web accessibility, enabling visually impaired users to navigate and understand web content using screen readers and other assistive technologies.
SEO
Alt text provides search engines with valuable information about the content and context of images, which can improve image search rankings and overall page visibility.
User Experience
It ensures that users can still understand the content of a webpage even if images fail to load, improving the overall user experience.
Why It Matters
Importance in SEO
Image Search Rankings
Alt text is a ranking factor for image search, helping images rank higher in Google Images and other image search results.
General Organic Search
While not a direct ranking factor for general organic search, alt text contributes to the overall understanding of page content by search engines, which can indirectly influence page rankings.
User Accessibility
It is essential for ensuring web content is accessible to all users, regardless of their abilities, which can positively impact brand reputation, traffic, and conversion rates.
Impact on Website Performance
Traffic and Engagement
Proper use of alt text can drive valuable traffic from image searches and improve user engagement by providing a better understanding of image content.
User Experience and Accessibility
It enhances the user experience by ensuring that all users can access and understand the information presented on a webpage, even if they cannot view the images.
Best Practices
Writing Effective Alt Text
Be Descriptive and Concise
Write alt text that briefly but thoroughly describes the image. There is no specific character limit, but it should be relevant and useful.
Include Target Keywords
If possible, include target keywords in the alt text to help with SEO, but ensure it remains descriptive and natural.
Avoid Decorative Images
Do not write alt text for purely decorative images; instead, use a null (empty) alt attribute to avoid distracting users with visual impairments.
Tools and Strategies
Content Management Systems (CMS)
Most CMSs have dedicated fields for alt text, making it easier to add without editing HTML code directly.
SEO Tools
Tools like Semrush’s SEO Writing Assistant can remind you to add image alt text and provide suggestions for readability and SEO.
Related Terms
Internal Linking Structure
Image SEO
Optimizing images for search engines, including best practices for image file names, titles, and schema markup.
Web Accessibility
Ensuring web content is accessible to all users, including those with disabilities, through the use of alt text, captions, and other accessibility features.
On-Page Optimization
Optimizing various elements of a webpage, including title tags, H1 tags, and content, to improve search engine rankings.
Screen Readers and Assistive Technologies
Tools used by visually impaired users to navigate and understand web content.
Conclusion
Alt text is an essential component of web accessibility, providing a vital function for visually impaired users while simultaneously benefiting SEO efforts. By correctly implementing alt text, webmasters can ensure that their content is accessible and that their images are indexed and ranked appropriately by search engines. This contributes to a better user experience overall, making web content more inclusive and potentially improving traffic from both image and organic searches. Following best practices for writing effective alt text, and utilizing tools and strategies to assist in its implementation, can further enhance a website’s performance and accessibility.
