Quick answer: Alt text is a textual description of an image that helps screen readers convey the image's content to visually impaired users and assists search engines in understanding the image's context. Effective alt text enhances accessibility and contributes to image SEO, which can improve a website's visibility in search results.

How it actually works

Alt text functions by providing a textual alternative to images on a webpage. When a screen reader encounters an image, it reads the alt text aloud, allowing visually impaired users to understand the image's content. For search engines, alt text serves as a signal to understand the image's context and relevance to the surrounding content. This is crucial because search engines cannot "see" images but can index text. Alt text is embedded within the HTML of a webpage using the alt attribute in the <img> tag. This attribute should be concise yet descriptive, capturing the essence of the image without being overly verbose. For example, if an image depicts a sunset over a mountain range, the alt text might read "sunset over mountains with orange and pink sky." Properly implemented alt text can improve both user experience and search engine optimization by making content more accessible and providing additional context to search engines. This dual function is essential for sites aiming to reach a broader audience, including those relying on assistive technologies.

A concrete worked example

Consider an ecommerce store selling shoes. An image of a red sneaker might have the alt text: "Red sneaker with white laces and rubber sole." This description provides enough detail for screen readers to convey the image's content to users who cannot see it. It also helps search engines understand that the image is relevant to searches related to red sneakers. In contrast, an alt text like "shoe" would be too vague, while "Red sneaker with white laces, rubber sole, and brand logo on the side" might be unnecessarily detailed. The key is to strike a balance between being descriptive and concise. This approach not only aids accessibility but also enhances the image's SEO value, potentially improving the page's ranking for relevant search queries. For instance, if a user searches for "red sneakers with white laces," the detailed alt text increases the likelihood that the image will appear in search results, driving more targeted traffic to the site.

What it is commonly confused with

Alt text is often confused with image captions and titles. While all three provide textual information about an image, they serve different purposes. Alt text is primarily for accessibility and SEO, offering a description for screen readers and search engines. Image captions, on the other hand, are visible to all users and provide context or commentary directly beneath the image. For example, a caption might read "Our latest collection of sneakers," giving users additional context about the image. Titles, which appear when a user hovers over an image, offer additional information but are not used by screen readers or search engines for indexing. Understanding these distinctions is crucial for effectively using each element to enhance user experience and SEO. Unlike captions and titles, alt text is not visible on the webpage, emphasizing its role in accessibility and search engine indexing. This distinction ensures that each element is used appropriately to maximize both user engagement and search engine performance.

What it means specifically on Shopify

On Shopify, alt text is a critical component of product page optimization. Shopify allows merchants to add alt text to images through the admin panel, making it straightforward to enhance both accessibility and SEO. Properly implemented alt text can improve a Shopify store's visibility in image search results, potentially driving more traffic to the site. Shopify's platform is designed to be SEO-friendly, and using alt text effectively aligns with best practices for SEO for ecommerce product pages. Merchants should ensure that alt text is descriptive and relevant to the product, as this can influence how search engines rank the page. For example, a product image of a blue denim jacket should have alt text like "Blue denim jacket with button closure," which accurately describes the product. Shopify's integration with various SEO tools can help merchants audit and optimize their alt text for better performance. These tools can provide insights into how well the alt text aligns with search engine guidelines and suggest improvements where necessary.

The mistakes people actually make

Common mistakes with alt text include being too vague, overly detailed, or omitting it altogether. Some merchants use generic phrases like "image" or "photo," which provide no value for accessibility or SEO. Others might stuff keywords into alt text, thinking it will boost SEO, but this can lead to penalties from search engines for keyword stuffing. For instance, an alt text like "buy cheap red sneakers online free shipping" is not only unhelpful but could also harm SEO efforts. Another mistake is neglecting to update alt text when images are changed or updated, leading to mismatches between the image and its description. On Shopify, failing to utilize alt text can result in missed opportunities for improving search visibility and accessibility. Merchants should regularly review their alt text as part of a content audit to ensure it remains relevant and effective. This involves checking that the alt text accurately reflects the image content and aligns with current SEO practices.

How to check or verify it yourself

To verify alt text on your Shopify store, you can inspect the HTML code of your webpage. Right-click on an image and select "Inspect" to view the <img> tag and its alt attribute. Ensure that the alt text is descriptive and relevant to the image. You can use tools like the Image Alt Text Generator & Checker to evaluate the effectiveness of your alt text. This tool can help identify missing or inadequate alt text, providing suggestions for improvement. Regularly checking your alt text as part of an SEO audit can help maintain accessibility standards and optimize your store's SEO performance. By ensuring that all images have appropriate alt text, you can enhance both user experience and search engine visibility. This process involves not only checking for the presence of alt text but also assessing its quality and relevance to ensure it meets both accessibility and SEO criteria.