Writing alt text for images requires a focus on descriptive clarity that helps search engines understand the subject matter of image files. Google recommends descriptive alt text to ensure your visual assets provide value to both human users and automated crawlers. By explicitly defining what is in an image, you allow search engines to associate your site with relevant queries. This practice bridges the gap between visual content and text-based indexing, serving as a pillar for organic search performance across your web properties.
Why does Google care about your image descriptions?
Search engine algorithms rely on text to interpret visual data. When a spider crawls your website, it cannot see an image in the same way a human visitor does. Instead, it reads the underlying code to determine the context and relevance of the image to the surrounding page content. If your file names are generic, such as ‘IMG_9921.jpg’, the alt attribute becomes the primary source of truth for the bot.
Providing accurate descriptions helps your media appear in image search results, which can drive traffic back to your site. This is especially important for e-commerce platforms where product visuals often serve as the first point of contact for potential customers. When a user searches for a specific item, Google uses the alt text to decide if your product image matches the search intent, effectively acting as a ranking factor for visual discovery.
How can you write effective alt text for e-commerce?
Writing for e-commerce requires a balance between descriptive accuracy and keyword relevance. You should describe the product as if you were explaining it to someone who cannot see it. Start with the main subject, then include details like color, material, and brand. Avoid keyword stuffing, as this creates a negative experience for screen reader users and may be perceived as spam by search algorithms.
For example, if you manage a Shopify store selling organic cotton shirts, a poor alt tag would be ‘shirt’. A better, high-ranking tag would be ‘men’s navy blue organic cotton crew neck shirt’. This provides enough detail to be helpful while naturally incorporating keywords that a potential buyer might use in a search query. It serves the dual purpose of accessibility compliance and search engine optimization.
Best practices for descriptive image labeling
- Be concise: Keep your descriptions under 125 characters to ensure they are read fully by common screen readers.
- Avoid redundant phrases: Do not start with ‘image of’ or ‘picture of’ because the browser already identifies the element as an image.
- Use your target keywords naturally: Include the primary keyword for the page only if it accurately describes the image content.
- Focus on context: If the image is a decorative element, use an empty alt attribute (alt=””) to tell screen readers to ignore it.
- Maintain consistency: Use the same naming convention for product categories across your entire site to build strong topical relevance.
Should you use keywords in your alt text?
Using keywords in alt text is a standard practice, but it must be done with caution. You want to describe the image in a way that includes relevant terms without forcing them into a sentence where they do not belong. Google recommends descriptive alt text, which implies a focus on human readability rather than machine manipulation. If your primary keyword fits naturally, include it, but prioritize the user experience above all else.
In a typical account audit at Alien Road, we often see websites that have missed opportunities by ignoring alt text on product galleries. If you have a gallery of interior design photos, label each one based on the specific style or room type. Instead of ‘living room 1’, use ‘modern minimalist living room with grey sofa and oak coffee table’. This specific level of detail helps search engines index your site for long-tail queries.
How to handle decorative images versus informative ones
Not every image on your website needs a long, detailed description. Decorative images—such as background textures, borders, or purely aesthetic icons—do not convey information that a visually impaired user needs to understand the page content. For these items, you should use an empty alt attribute, which looks like alt=”” in your HTML. This prevents screen readers from announcing unnecessary information.
Informative images, however, require descriptive text that explains the function or the data within the graphic. If you are displaying a chart or a screenshot of a software dashboard, the alt text should summarize the key findings or the purpose of the visual. This ensures that users with disabilities get the same information as sighted users, which is a core component of modern web accessibility standards.
Where can you update alt text in common platforms?
- WordPress: Go to your Media Library, click on an image, and enter your text in the Alt Text field located in the Attachment Details sidebar.
- Shopify: In the product editor, click on the image, select ‘Add alt text’, and save your changes in the modal window that appears.
- Wix: Right-click the image in the editor, select ‘Settings’, and find the ‘What’s in the image?’ field to input your description.
- Squarespace: Click the image block, select ‘Edit’, and find the ‘Alt Text’ field within the image settings tab.
Common mistakes to avoid when writing alt text
One of the most frequent errors is leaving the alt text field blank on important images, such as product photos or infographics. This is a missed chance to rank in image search and a barrier for accessibility. Another mistake is using the file name as the alt text. If your file is named ‘IMG_554.jpg’, copying that name into the alt field provides zero value to the user or the search engine.
Avoid repetitive text if you have multiple images of the same product from different angles. Instead of repeating the same description, differentiate them by mentioning the angle or the feature being shown. For example, use ‘front view of leather handbag’ and ‘side view of leather handbag’. This helps the search engine understand the specific context of each unique file on your product page.
Where to start this week
Start by conducting a quick audit of your top ten most visited pages this week. Check the alt text for every image on these pages and update any that are missing or generic. Prioritize your product images or your primary service images, as these are the most likely to drive organic traffic through visual search. Once you update these, monitor your traffic in Google Search Console to see if you notice a change in your search visibility over the next month.
Consistency is your best friend when managing a large catalog. Create a simple spreadsheet to track your images and their corresponding alt text. This will help you maintain a standard format across your site and ensure that you are not overlooking new uploads. By spending just a few hours optimizing your existing image library, you can significantly improve your site’s accessibility and search engine performance without needing to change your core content strategy.
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