The Role of Alt Text in SEO, How to Use It Effectively

Alt text, or alternative text, is essential for both accessibility and SEO. From my experience, well-optimized alt text not only enhances accessibility for visually impaired users but also helps images rank in Google’s image search, driving additional organic traffic. This guide covers how to use alt text effectively to support both user experience and SEO goals.

1. Understanding the Role of Alt Text in SEO and Accessibility

Alt text describes an image's content to those who cannot see it, including visually impaired users and search engine bots. For SEO, alt text helps Google and other search engines understand the context of an image, which can influence image search rankings and improve overall page relevance.

Benefits of Alt Text for SEO

Enhanced Image Search Visibility: Alt text can make images rank in image search, which can drive traffic.
Improved On-Page Relevance: Descriptive alt text provides additional context for the main content.
Accessibility Compliance: Alt text ensures accessibility, which can improve site usability and reputation.

2. Crafting Effective Alt Text

When writing alt text, aim for concise descriptions that accurately represent the image while including relevant keywords. Overloading alt text with keywords is unnecessary and can even harm SEO efforts. Google values natural, descriptive language that genuinely explains the image.

Tips for Writing Descriptive Alt Text

Be Specific and Descriptive: Clearly describe what the image shows. For instance, instead of using "dog" as alt text, write "Golden Retriever playing in a park."
Incorporate Keywords Naturally: Use keywords that relate to the image and context without overstuffing. For instance, "Golden Retriever playing fetch in Central Park" includes a relevant keyword without forcing it.
Limit Character Count: Alt text should ideally be under 125 characters to ensure readability by screen readers.

3. The SEO Impact of Alt Text in Image Optimization

Optimizing images is crucial for page speed, accessibility, and SEO. When coupled with file names, captions, and surrounding text, alt text can contribute significantly to how search engines interpret an image. Image optimization techniques, such as compressing files and using descriptive file names, can further enhance the benefits of alt text.

Example of Optimized Alt Text

If you have an image of a chart showing SEO growth, consider alt text like “line chart depicting monthly SEO traffic growth from 2022 to 2023.” This not only describes the image but also includes keywords like "SEO traffic growth" that are relevant to the page.

For more information on optimizing images, check out Image Optimization Techniques for Better Rankings.

4. Common Alt Text Mistakes to Avoid

While alt text is simple to add, many website owners and bloggers still make mistakes that reduce its effectiveness. Here are some common pitfalls to avoid:

Keyword Stuffing: Cramming keywords into alt text can lead to a poor user experience and is often penalized by search engines.
Leaving Alt Text Blank: Unless the image is purely decorative, all images should have alt text to ensure accessibility.
Describing Irrelevant Details: Only include information relevant to the image’s context. Avoid redundant phrases like “image of” or “picture of” since screen readers already identify elements as images.

5. Integrating Alt Text with Surrounding Content

For alt text to be effective, it should complement the surrounding content. The context in which the image is placed matters, as search engines use the page's content to understand the image's relevance.

Strategies for Contextual Alt Text

Align Alt Text with Headings: If the image appears under a specific heading, ensure the alt text relates to that heading.
Use Relevant Keywords in Surrounding Text: Keywords in the surrounding paragraphs reinforce the image's relevance, boosting SEO.
Provide Additional Context with Captions: When appropriate, use captions to offer supplementary information. Captions, along with alt text, help search engines and users understand image relevance.

6. The Role of Alt Text in Google Image Search

Google Image Search can drive substantial traffic to websites, especially for e-commerce sites and content-heavy blogs. Optimized alt text can make a significant difference in whether an image appears in image search results.

Best Practices for Alt Text in Google Image Search

Prioritize Descriptive Keywords: Use terms that a user might search for, such as “sustainable bamboo coffee table” rather than “table.”
Use Unique Alt Text for Each Image: Avoid using the same alt text for multiple images, as unique descriptions improve search engine understanding.
Include Contextual Keywords Sparingly: Terms like “New York” or “eco-friendly” add value if they are directly relevant to the image.

7. Enhancing Accessibility with Alt Text

Alt text plays a vital role in making websites accessible to users with visual impairments. Many countries, including the U.S. and the E.U., have web accessibility guidelines that recommend or require alt text for images.

Tips for Accessibility-Driven Alt Text

Describe Functional Images: For interactive elements like buttons or links with images, describe the function rather than the image itself, e.g., "Search button."
Avoid Using “Image of” or “Picture of”: Screen readers automatically announce images, so stating “image of” is redundant.
Skip Decorative Images: If an image is purely decorative and doesn’t add value to the content, use a blank alt attribute (alt="") to signal to screen readers to ignore it.

8. Using Alt Text to Optimize Google My Business Photos

For local businesses, optimizing alt text on Google My Business (GMB) photos can enhance local SEO. Using alt text that describes your business, location, and service offerings in GMB photos can increase visibility in Google search results.

Example of GMB Alt Text Optimization

If you own a bakery, use alt text for your GMB images like “display of fresh pastries and bread at Sunshine Bakery, downtown Seattle.” This alt text includes keywords related to the business and location, which boosts local SEO.

For more on boosting local SEO, see How to Rank Higher on Google Maps.