Alt text

Alt text (alternative text) is used to describe the appearance and function of images on the web. It's displayed in place of an image if an image file can't be loaded, and it's critical for making content accessible to users with visual impairments. It's also great for SEO.

Whether you're adding a graphic to an email or embedding a chart or graph in a blog post, you need to include alt text. The exact language will depend on the image, but here are some (abridged) tips from the pros at Moz that should always apply.

1. Describe the image as specifically as possible. Alt text is designed to provide text explanations of images for users who are unable to see them. If an image doesn't convey any meaning/value that can be written out, it should be left out.

2. Keep it short. Most screen readers cut off alt text at around 125 characters, so it's best to stick to that character count or less.

3. Use your keywords Alt text provides another opportunity to include target keyword(s) and thus signal to search engines that your page is relevant to a given search query.

4. Avoid keyword stuffing. Google won't dock you points for poorly written alt text, but you'll be in trouble if you use it as an opportunity to cram in too many unrelated keywords.

5. Don't add "image of" or "picture of" in your alt text. It's already assumed that your alt text is referring to an image, so there's no need to specify that.

6. Don’t neglect form buttons. If you're using an image as a button, give it an alt attribute. Image buttons should have alt text that describes the function of the button, such as "Search", "Apply now," or “Sign up."

Here's an example of good alt text:

• Screenshot showing Reach's new mosaic product page layout option.

Here's an example of bad alt text:

• Image showing example.

Remember that all browsers and email clients handle alt text a little differently. Supplement images with standard captions when possible.