How to Write Good Alt Text

Images are powerful tools for communication, breaking up text, illustrating points, and making your content engaging. But for search engines and users with visual impairments, images can be just blank spaces. This is where alt text, short for alternative text, comes in. Writing good alt text is a crucial, yet often overlooked, aspect of on-page SEO and web accessibility. It’s not just about describing an image; it’s about providing context, enhancing user experience, and helping search engines understand your content better.

What is Alt Text and Why Does it Matter?

Alt text is an HTML attribute that provides a textual description of an image. When an image fails to load, or when a user is using a screen reader, the alt text is displayed or read aloud. This serves two primary purposes:

• Accessibility: It allows visually impaired users to understand the content of the image, making your website accessible to a wider audience.
• SEO: Search engines cannot "see" images. Alt text provides them with information about the image and its relevance to the surrounding content, which can improve your search rankings.

Think of it as a brief, descriptive caption that bridges the gap between visual content and textual understanding. Properly optimized alt text can contribute significantly to your overall On-Page SEO.

The Anatomy of Effective Alt Text

Writing compelling alt text isn't rocket science, but it does require a thoughtful approach. Here are the key components of good alt text:

Be Descriptive and Specific

The primary goal of alt text is to convey the content and function of the image. Avoid generic descriptions. Instead of "dog," consider "golden retriever puppy playing fetch in a park."

• Good Example: "A smiling woman in a blue dress holding a bouquet of roses."
• Bad Example: "Image" or "Woman."

The more specific you are, the better search engines and assistive technologies can interpret the image. If the image is a graph, describe what the graph represents. If it's a product, mention the product name and key features.

Keep it Concise

While being descriptive, aim for brevity. Screen reader users don't want to listen to lengthy paragraphs. Generally, keeping alt text under 125 characters is a good practice, although there's no strict limit. Get to the point quickly and effectively.

Use Keywords (Naturally)

Integrating relevant keywords into your alt text can help search engines understand the context of your page. However, this must be done naturally and without stuffing. If your article is about "baking sourdough bread," and an image shows the process, your alt text might be "baker scoring a sourdough loaf before baking."

• Keyword Stuffing Example: "dog, puppy, cute dog, golden retriever, dog playing, dog in park, dog." (This is bad!)
• Natural Keyword Integration: "Golden retriever puppy happily fetching a ball in a sunny park."

Remember that keyword prioritization is essential for effective SEO, and alt text is just one piece of the puzzle. Understanding how to prioritize keywords will help you place them strategically across your content.

Avoid Redundancy

Don't start your alt text with phrases like "image of," "picture of," or "graphic of." Screen readers already announce that it's an image. Get straight to the description.

• Redundant: "Image of a red sports car."
• Better: "Red sports car driving on a coastal highway."

Consider the Context of the Page

The alt text should complement the surrounding content. If an image is used to illustrate a specific point in your article, your alt text should reflect that connection. For instance, if you're discussing the benefits of a particular software, and the image shows a screenshot of its user interface, your alt text should describe that interface in relation to the benefits being discussed.

Function Over Form

If an image is a functional element, like a "buy now" button disguised as an image, your alt text should describe its function.

• Example: "Buy the latest smartphone model now."

This is crucial for users who cannot see the button's visual cues.

When to Use Alt Text and When Not To

While most images benefit from alt text, there are nuances:

Images That Need Alt Text

• Informative Images: Charts, graphs, diagrams, illustrations that convey data or information.
• Actionable Images: Buttons, logos, icons that users interact with.
• Content-Carrying Images: Photos, artwork, or graphics that are integral to understanding the page's content.
• Decorative Images (with a purpose): Even if an image is primarily decorative, if it adds to the overall aesthetic and user experience in a meaningful way, it might warrant a brief description.

Images That May Not Need Alt Text (or require empty alt text)

• Purely Decorative Images: If an image serves no informational or functional purpose and is purely for aesthetic appeal, you can use an empty alt attribute (alt=""). This tells screen readers to skip the image entirely, preventing unnecessary interruption for visually impaired users.

  • Example: A subtle background pattern or a small decorative border.

• Images Already Explained: If an image is immediately followed by a detailed textual description, you might consider a very brief alt text or even alt="" if the text fully covers the image's essence. However, it's generally safer to provide a concise description.

How to Implement Alt Text

Implementing alt text is straightforward, as it's an HTML attribute. When you upload an image to your website through a Content Management System (CMS) like WordPress, Shopify, or Squarespace, there will typically be a field labeled "Alt Text" or "Alternative Text" where you can enter your description.

Here's a basic HTML example:

<img src="puppy.jpg" alt="Golden retriever puppy happily fetching a ball in a sunny park">

The alt attribute is placed within the <img> tag.

Common Mistakes to Avoid

• Ignoring Alt Text Altogether: The most common mistake is leaving the alt text field blank.
• Over-Optimization (Keyword Stuffing): Cramming too many keywords into alt text will hurt your SEO and user experience.
• Generic Descriptions: "Picture" or "Image" provides no value.
• Misleading Descriptions: The alt text should accurately reflect the image's content.
• Not Considering Accessibility: Forgetting that alt text is a vital accessibility feature.

Alt Text and Image SEO

Alt text is a significant factor in image SEO. When users perform an image search, search engines use alt text, along with the image file name, surrounding text, and other signals, to determine relevance and rank images.

• Image File Names: While less impactful than alt text, descriptive file names (e.g., golden-retriever-puppy-park.jpg instead of IMG_1234.jpg) also help search engines.
• Contextual Relevance: Ensure your images are relevant to the content of the page. This improves user engagement and indirectly benefits SEO. Understanding how page content influences search engine perception can also be informed by understanding how to use AI in SEO.
• Image Captions: While not a replacement for alt text, captions can provide additional context for users and search engines.

Advanced Alt Text Strategies

For more complex scenarios, consider these approaches:

Complex Images (Charts, Graphs, Infographics)

For images that convey a lot of data, a short alt text might not suffice. In such cases:

• Provide a Concise Summary in Alt Text: Briefly describe the main takeaway of the graphic.
• Offer a Detailed Description Nearby: Place a paragraph or table below the image that elaborates on the data presented.
• Link to a More Detailed Page: If the graphic is very complex, link to a separate page with a full explanation.

Example: alt="Bar chart showing a 30% increase in website traffic from organic search in Q4 2023." Followed by a detailed explanation of the chart's findings.

Functional Images (Icons, Buttons)

As mentioned, focus on the action. Example: For a shopping cart icon: alt="View your shopping cart."

Images as Links

If an image is used as a link, its alt text should describe the destination or action of the link. Example: If a company logo links to the homepage: alt="Ithile - Go to homepage."

Images with Text

If an image contains text, try to include that text in the alt text, along with any other relevant descriptive information. Example: If an image is a poster with the text "Summer Sale - 50% Off," your alt text could be: alt="Summer Sale poster with '50% Off' prominent."

Testing Your Alt Text

You can check your alt text in a few ways:

1. View Page Source: Right-click on an image on your webpage and select "Inspect" or "View Page Source." Look for the <img> tag and its alt attribute.
2. Browser Extensions: Several browser extensions are designed to audit image alt text for accessibility and SEO.
3. Screen Readers: The best way to understand the user experience for visually impaired individuals is to use a screen reader (like NVDA, JAWS, or VoiceOver) to navigate your site.

The Impact of Good Alt Text on User Experience

Beyond SEO, well-written alt text significantly enhances user experience.

• Improved Comprehension: Users can grasp the meaning of content even if images don't load or if they rely on assistive technologies.
• Faster Loading: In cases where images fail to load, descriptive alt text still provides some information, preventing a complete breakdown in communication.
• Enhanced Engagement: When users can access and understand all elements of your content, they are more likely to stay engaged. This also relates to how users interact with different page structures, like understanding how to optimize pagination effectively.

Frequently Asked Questions about Alt Text

What is the maximum length for alt text?

There isn't a strict character limit, but it's best to keep alt text concise and descriptive, generally under 125 characters. Screen readers may truncate longer descriptions.

Should I use keywords in my alt text?

Yes, but only if they are relevant and integrated naturally. Keyword stuffing will harm your SEO and user experience. Focus on accurate descriptions first.

What if an image is purely decorative?

For purely decorative images, use an empty alt attribute: alt="". This tells screen readers to skip the image, improving the experience for visually impaired users.

How does alt text affect image search rankings?

Search engines use alt text to understand what an image is about, which helps them rank images in search results. Relevant and descriptive alt text can lead to higher visibility in image searches.

Can I use the same alt text for multiple images?

No, each image should have unique alt text that accurately describes that specific image. Duplicative or generic alt text provides little value to users or search engines.

Is alt text the same as image captions?

No. Alt text is an HTML attribute that is invisible to most users but read by screen readers. Captions are visible text displayed below or near an image, providing additional context for all users.

Conclusion

Mastering the art of writing good alt text is a fundamental step towards creating a more accessible and SEO-friendly website. It’s a practice that benefits everyone, from visually impaired users to search engines themselves. By being descriptive, concise, and context-aware, you can transform your images from mere visual elements into powerful tools for communication and discoverability.

At ithile, we understand the intricate details that contribute to a successful online presence. If you're looking to enhance your website's accessibility and SEO performance, consider exploring our SEO consulting services. We can help you implement best practices, including optimizing your alt text, to ensure your content reaches the widest possible audience and achieves its full potential.