Image alt text best practices involve creating descriptive, concise text that explains the content and purpose of an image to both search engines and users who rely on screen readers. Alt text serves as a text-based alternative for images, ensuring that the information conveyed visually is accessible to everyone. By writing clear and descriptive text, you help search engines understand the subject matter, which can improve the visibility of your media in search results. This practice is a standard requirement for maintaining a professional and inclusive website.
Why is image alt text important for your website?
The primary function of alt text is accessibility. Users with visual impairments often use screen reader software to interpret the content on a web page. When these tools encounter an image, they read the alt text aloud to the user. Without this text, the user may hear a file name or nothing at all, which creates a barrier to understanding the page content. Providing accurate descriptions ensures that your site remains usable for a wider audience, which is a core tenet of good web development.
Beyond accessibility, search engines use alt text as a data point to index images. While modern algorithms are good at identifying visual elements, text descriptions provide the necessary context to confirm the subject matter. If your image depicts a specific product, location, or concept, the alt text helps the search engine associate that image with relevant search queries. This helps your media appear in image-specific search results, driving additional traffic to your site through organic discovery.
What makes an effective alt text description?
An effective alt text description is specific, accurate, and concise. You should focus on describing exactly what is in the image, rather than using the space to stuff keywords. A common pattern is to write a single sentence that captures the main focus of the visual. Avoid generic phrases like ‘image of’ or ‘picture of’, as screen readers already identify the element as an image. Instead, get straight to the subject to provide value immediately.
How do you write alt text for different types of images?
Different images require different approaches to description. For informative images, such as charts or diagrams, your goal is to summarize the key data points or the message being communicated. For decorative images, such as background shapes or icons that add no functional information, you can leave the alt attribute empty (alt=””). This tells screen readers to skip the element, preventing unnecessary interruptions for the user. Here are some guidelines for common scenarios:
- Product images: Include the product name, color, and key features that a user would notice at a glance.
- Charts and graphs: Describe the main trend or the most important data point shown in the visual.
- Informational photos: Capture the context of the photo, such as the location or the specific action occurring.
- Decorative images: Use an empty string to allow screen readers to ignore the element.
- Button images: Describe the function of the button, such as ‘Submit form’ or ‘Download report’.
What are the most common mistakes to avoid?
Keyword stuffing is the most frequent mistake when writing alt text. Trying to cram as many relevant terms as possible into the description often results in text that is unhelpful to users and suspicious to search engines. If you have an image of a red running shoe, your alt text should simply be ‘Red running shoe on a white background’. It should not be ‘red running shoes, cheap running shoes, buy running shoes online’, as this provides no actual description.
Another common error is ignoring the context of the surrounding text. If your article already discusses the history of local architecture in the paragraph above an image, you do not need to repeat that entire context in the alt text. Focus on what is unique about that specific image. Ensure your descriptions remain objective and descriptive to provide the best possible experience for all visitors.
How Alien Road applies image alt text best practices
At Alien Road, we integrate alt text optimization into every content production cycle. When we audit a client site, we look at the existing media library to identify gaps in accessibility. For a typical account, we begin by reviewing the highest-traffic pages to ensure every non-decorative image has a descriptive tag. We use a documented process to ensure consistency across the site, checking that descriptions match the intent of the content provided by the client.
We also incorporate alt text training into our workflow. When preparing new content, our team drafts descriptions that align with the page’s primary topic while remaining unique to each image. For example, if a client is launching a new product category, we advise them to use specific model numbers and variations in the alt text. This approach ensures that the media remains relevant and useful for both human visitors and search engine crawlers over time.
Which technical settings should you verify?
Most content management systems make it easy to add alt text. If you are using a platform like WordPress, you can find the ‘Alt Text’ field in the media attachment details screen. Always check that your images are saved with descriptive file names before you upload them. While the alt text is the priority, a file name like ‘red-running-shoe.jpg’ is better than ‘IMG_5432.jpg’ because it provides a secondary signal to search engines about the image content.
- Check your media library for images missing the alt attribute.
- Ensure your primary images have unique, descriptive text.
- Audit your site periodically to catch new uploads that lack descriptions.
- Verify that decorative images are tagged correctly to be ignored by screen readers.
- Keep descriptions under 125 characters to ensure they are read fully by most screen readers.
How to start implementing these changes this week?
Start by identifying the top 10 pages on your website that generate the most traffic. These are your priority targets for optimization. Open these pages and inspect the images one by one. Use a screen reader or a browser extension to see how the alt text is currently being announced. If you find missing or poor-quality descriptions, draft new ones that are specific and helpful. By focusing on your most visible pages first, you can see a direct impact on the accessibility and search quality of your most important content.
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