Image SEO: Alt Text Best Practices for Better Rankings

Alt text is one of the most overlooked elements in SEO. It takes seconds to write, costs nothing, and directly impacts how search engines understand your images. Done well, it also makes your site accessible to visually impaired users. Here is how to write alt text that serves both purposes.

What Alt Text Actually Does

Alt text (alternative text) is an HTML attribute that describes an image. It serves three functions:

1. Screen readers read it aloud to visually impaired users, giving them context about the image.

2. Search engines use it to understand image content since they cannot "see" photos the way humans do.

3. Broken images display the alt text when an image fails to load, so users still get context.

The HTML looks like this:

`html

<img src="product-photo.jpg" alt="Red leather wallet with brass zipper on white background">

`

The Anatomy of Good Alt Text

Good alt text is specific, concise, and descriptive. Follow these principles:

• Describe what you see, not what you think. "Woman typing on laptop" is better than "Productivity at work."
• Be specific. "Golden retriever puppy sitting on grass" beats "dog."
• Keep it under 125 characters. Screen readers may truncate longer text, and search engines give diminishing returns past this length.
• Skip "image of" or "photo of". Screen readers already announce that the element is an image. Starting with "image of" is redundant.
• Include relevant keywords naturally. If the page is about leather wallets, mentioning "leather wallet" in the alt text is appropriate and helpful. Keyword stuffing is not.

Alt Text Examples by Context

Product Images

• Bad: "product1.jpg"
• Okay: "Blue running shoes"
• Good: "Nike Air Zoom Pegasus 41 blue running shoes, side view"

Blog Post Images

• Bad: "blog header"
• Okay: "Person working on computer"
• Good: "Developer optimizing website images in code editor"

Infographics

• Bad: "infographic"
• Okay: "Image format comparison chart"
• Good: "Bar chart comparing JPEG, PNG, and WebP file sizes for a sample photograph"

Decorative Images

If an image is purely decorative and adds no informational value, use an empty alt attribute:

`html

<img src="decorative-border.png" alt="">

`

This tells screen readers to skip the image entirely.

Common Alt Text Mistakes

• Leaving alt text empty on meaningful images. Every informational image needs alt text. Empty alt attributes should only be used for decorative images.
• Stuffing keywords. "Best cheap leather wallet buy leather wallet online leather wallet sale" is spam. Search engines penalize this.
• Using the filename. "IMG_4392.jpg" tells nobody anything. Always write descriptive text.
• Being too vague. "A chart" does not help anyone. Describe what the chart shows.
• Duplicating the caption. If the image has a visible caption, the alt text should add context the caption does not provide, not repeat it word for word.

Alt Text and Image SEO Beyond Alt Tags

Alt text is just one piece of image SEO. For the full picture:

• Use descriptive filenames. Rename "DSC_0042.jpg" to "red-leather-wallet.jpg" before uploading.
• Compress images to improve page load speed. Use the Browser Image Converter Image Compressor to reduce file sizes without visible quality loss.
• Choose the right format. WebP and AVIF load faster than JPEG and PNG. Use the Format Converter to switch formats.
• Resize to display dimensions. Serving a 4000 px image that displays at 800 px wastes bandwidth. The Image Resizer handles this in seconds.
• Add structured data. Use schema.org ImageObject markup to give search engines even more context.
• Create an image sitemap. This helps search engines discover images that might not be found through normal crawling.

How to Audit Your Existing Alt Text

1. Run your site through a tool like Lighthouse or Screaming Frog.

2. Export a list of all images with missing or empty alt attributes.

3. Prioritize pages with the most traffic.

4. Write descriptive alt text for each image, following the guidelines above.

5. Re-crawl to confirm all images now have appropriate alt text.

Conclusion

Writing good alt text is a small effort with outsized returns. It improves accessibility, helps search engines index your images, and can drive meaningful traffic through Google Image Search. Combine strong alt text with optimized image files from Browser Image Converter, and your visual content will work harder for you on every front.