Alternative text (alt text) also known as “alt attributes” is a word or phrase that can be inserted as an attribute in HTML code to describe the appearance and function of an image on a page. Alt tags describe images to search engine crawlers, helping them index an image properly.
Why Is Alternative Text Important?
Alt text is important for a couple of reasons. First, it improves accessibility. People who are visually impaired need the alt text to better understand what’s on the screen. Without alt text, there’s no way to communicate the content of the image to the user.
Alt text can improve topical relevance because sometimes the context is “locked away” in images that Google can’t read, and this is where the alt text comes in handy. Without alt text, Google can’t read the specifics of an image.
Don’t forget that Google Images is the world’s second-largest search engine, which means that there’s an opportunity to drive traffic from Google Images. So, among other things, alt text can help you rank in Google Images.
Example of Alt text:
<img src=”Little-girl-spraying-houseplant-leaves-taking-care-of-plant-Monstera..jpg” alt=”Little girl spraying houseplant leaves, taking care of plant Monstera.“>
How to Write Good Alternative Text
Let’s start with the format. The optimal alt text is sufficiently descriptive but it shouldn’t be spammy.
The point is to describe the image as specifically as possible. Alt text is designed to provide a detailed text explanation of images for users who are unable to see them.
When it comes to length, keep your alt text relatively short. Keep the description around 125 characters long because that’s where most screen readers cut off alt text.
Alt text gives you a wonderful opportunity to include your target keyword on a page. It makes sense to include your keyword in the alt text but don’t forget to avoid spammy tactics — it’s possible to engage in keyword stuffing in the alt text. You can get in trouble for that, so focus on writing descriptive alt text that provides good context and description to the image.
Never use the image as text. This is because search engines can’t read text within your images, so, you should always use words to describe what you’re seeing.
For more complex images that require a longer description, use the longdesc HTML attribute.
If a form on your website uses an image as its “submit” button, don’t forget to give it an alt attribute. Don’t neglect form buttons.
Should I Add Alt Text to All Images?
Even though people often think this is the case, actually you don’t have to always add alt text to your image. If the image exists only for decorative purposes, you don’t need to add alt text.
Adding alt text to decorative images can only annoy visitors with screen readers and won’t add any SEO value.
However, If the image doesn’t require alt text it would be good to add an empty alt attribute. Because some screen readers read out file names in the absence of an alt attribute, most will skip those with empty ones.
Finally, if your image is truly only present for decorative purposes, then it should be a CSS item, not an HTML one.