Writing Effective Alt Text for Images

Writing Effective Alt Text for Images

What is Alt Text?

Alt text, short for alternative text, is an HTML attribute used to provide a textual description of an image on a webpage. This text is invisible to users unless the image fails to load or is accessed by assistive technologies like screen readers used by visually impaired individuals.

Why is Alt Text Important?

1. Accessibility:

Alt text is crucial for web accessibility. It allows people who are visually impaired or have difficulty processing visual information to understand the content and purpose of images on a page. Screen readers read aloud the alt text, conveying the image’s message.

2. SEO Benefits:

Search engines like Google rely on alt text to understand the context of images and their relevance to the surrounding content. Well-written alt text can improve your website’s SEO ranking by providing keywords and context for image searches.

3. Improved User Experience:

When images fail to load due to slow internet connections or other technical glitches, alt text serves as a placeholder, ensuring users still get an idea of the missing visual. This contributes to a smoother and less frustrating user experience.

How to Write Effective Alt Text:

1. Be Specific and Descriptive:

Clearly describe the image’s content in a concise manner. Avoid generic terms like image or picture. Instead, provide specific details that accurately represent what is shown, such as a golden retriever puppy playing with a red ball in a park.

2. Keep it Concise:

While being descriptive, aim for brevity. Most screen readers have a character limit for alt text, so keep it around 125 characters or less for optimal compatibility.

3. Context is Key:

Consider the image’s purpose within the context of the webpage. How does the image relate to the surrounding text? Your alt text should complement the content and provide valuable information to users who cannot see the image.

4. Avoid Keyword Stuffing:

While using relevant keywords is beneficial for SEO, avoid cramming in too many keywords into the alt text. This can come across as spammy and negatively impact your SEO. Focus on writing natural and descriptive text that accurately reflects the image.

5. Don’t Repeat Information:

If the surrounding text already describes the image in detail, avoid redundant information in the alt text. Instead, provide a brief summary or focus on specific details not explicitly mentioned in the text.

When to Leave Alt Text Blank:

1. Decorative Images:

If an image is purely decorative and doesn’t convey any essential information, you can leave the alt text blank. However, it’s important to indicate that the image is decorative by using an empty alt attribute: alt=. This tells screen readers to ignore the image, improving the browsing experience for visually impaired users.

2. Complex Images with Captions:

For images with intricate details or charts that require longer descriptions, consider providing a caption below the image. In such cases, the alt text can be brief and refer to the caption for a more comprehensive understanding.

Examples of Effective Alt Text:

Image: A photograph of a sunset over the ocean.

**Good Alt Text:** A vibrant orange and pink sunset over a calm ocean, with the silhouette of a sailboat in the distance.

Image: A product image of a pair of running shoes.

**Good Alt Text:** Nike Air Zoom Pegasus 38 running shoes in black and white colorway.


Writing effective alt text is crucial for creating an inclusive and accessible web experience. By providing concise, descriptive, and contextually relevant textual descriptions for your images, you enhance the user experience for all visitors, including those who are visually impaired. Additionally, well-written alt text contributes to improved SEO by providing search engines with valuable information about your visual content. By following the guidelines outlined in this article, you can optimize your website’s accessibility and ensure that your images are accessible to everyone.