Alt text (alternative text) is a crucial component of SEO and web accessibility, yet it’s often overlooked or misused. When used correctly, alt text helps search engines understand images, boosts your website’s visibility, and enhances the user experience for those with visual impairments. In this comprehensive guide, we’ll cover the best practices (and pitfalls) to keep in mind when writing alt text, ensuring your website remains both accessible and SEO-friendly.
What Is Alt Text?
Alt text is a brief description assigned to images on a website. This text appears when an image fails to load and is read aloud by screen readers to help visually impaired users understand the content of the image. It also informs search engine algorithms about the image’s subject matter, which helps with indexing and ranking in search results.
Why Alt Text Matters
- Accessibility: Alt text allows screen readers to describe images to visually impaired users, making the web more inclusive.
- SEO Benefits: Search engines can’t “see” images the way users do, so alt text helps them understand and index image content, improving your website’s overall SEO performance.
- User Experience: When images fail to load due to a slow connection or server error, alt text provides context to users about what the image was supposed to convey.
The Dos of Writing Alt Text
- Be Descriptive and Specific
Alt text should describe the content of the image in detail, without being overly verbose. Use clear language to explain what’s in the image and why it’s relevant.
- Example: For an image of a person typing on a laptop, write: “Person typing on a laptop with a cup of coffee next to them.”
- Incorporate Keywords (Naturally)
While alt text should be written primarily for accessibility, it’s also an opportunity to include relevant keywords. However, ensure the keywords fit naturally into the description and don’t overstuff them.
- Example: For an eCommerce product image of running shoes, you can include keywords like “blue running shoes with breathable mesh.”
- Keep It Concise
Alt text should be descriptive but concise. Aim for around 125 characters, as most screen readers cut off after this length. Focus on what is important about the image, and avoid unnecessary details.
- Example: “Woman running on a trail wearing blue running shoes.”
- Use Alt Text for All Functional Images
If the image serves a functional purpose (e.g., a button or navigation icon), the alt text should describe the function rather than the appearance.
- Example: For a “search” button icon, use: “Search button.”
- Use Alt Text for Important Visual Content
If the image conveys significant information that adds context to the surrounding content, ensure the alt text describes it.
- Example: For an infographic showing monthly sales, you could write: “Infographic of monthly sales growth, showing a 25% increase in July.”
The Don’ts of Writing Alt Text
- Don’t Use ‘Image of’ or ‘Picture of’
Avoid redundant phrases like “image of” or “picture of.” Screen readers already recognize the content as an image, so these words are unnecessary.
- Incorrect Example: “Image of a dog playing in the park.”
- Correct Example: “Dog playing in the park.”
- Don’t Keyword-Stuff
Keyword stuffing not only looks spammy but also detracts from the user experience. Always prioritize natural, relevant descriptions over SEO optimization.
- Incorrect Example: “SEO services, SEO marketing, SEO tools in one package.”
- Correct Example: “Comprehensive SEO tools and services in one package.”
- Don’t Leave Alt Text Blank (Unless It’s Decorative)
Purely decorative Images that add no meaning to the content (e.g., background designs) can have empty alt attributes (alt=””). However, for all other images, provide useful descriptions.
- Incorrect Example:alt=”” for a product image.
- Correct Example:alt=”Red leather handbag with gold accents.”
- Don’t Over-Describe
Be careful not to over-explain the image. Alt text is meant to give a summary, not a full narrative. Keep it focused on the essentials.
- Incorrect Example: “A young woman with brown hair, wearing a red dress, sitting at a wooden table, typing on a silver laptop while drinking a coffee.”
- Correct Example: “Woman typing on a laptop while drinking coffee.”
- Don’t Use Alt Text for Decorative Images
As mentioned earlier, purely decorative images, such as design elements or spacers, should have an empty alt attribute. This prevents screen readers from cluttering the user experience with unnecessary information.
- Correct Example for Decorative Image:alt=””
Best Practices for Image SEO
While alt text is crucial for both accessibility and SEO, it’s only one part of image optimization. To ensure your images are fully optimized for search engines, consider the following practices:
- Optimize Image File Names: Before uploading your image, rename the file to include relevant keywords. Instead of “IMG1234.jpg,” use “blue-running-shoes.jpg.”
- Use Descriptive Captions (If Relevant): Captions that accompany images can provide additional context to users and search engines.
- Compress Images for Fast Loading: Use tools like TinyPNG or JPEGmini to reduce image file sizes without sacrificing quality. Faster loading times improve both user experience and SEO.
- Use the Right Image Format: Choose the most appropriate image format for your website, such as JPEG for photos and PNG for graphics or logos. This ensures clarity and proper resolution.
Conclusion
Writing effective alt text is a balance between accessibility and SEO. By following these dos and don’ts, you can create alt text that not only improves the experience for all users, including those with visual impairments but also enhances your site’s SEO performance. Remember to be descriptive, concise, and mindful of keywords, and avoid common mistakes like keyword stuffing and over-description. Proper alt text can be a powerful tool for boosting your site’s visibility and inclusivity.
Start optimizing your alt text today to improve both accessibility and SEO for your website!