Everything we know about alt-texts, when to use them, and how to craft them.
An alt-text is a description of an image that’s shown to people who can’t see the image. Alt-texts help people with little or no vision who use assistive technologies, people who have turned off images, and search engines.
It might sound obvious, but an alt-text should describe the image in case an image doesn’t display or someone has trouble seeing it. The goal of alt-text is to give the necessary information from the image at a glance. It’s best to include only the necessary information.
|“People using computers.”||“Man and woman using laptops at a standing table, Illustration.”|
|“Man in a purple shirt and woman in blue pants are typing on laptops and there’s a plant on the floor nearby.”|
|“Man and woman using computers, illustrated by Jane Doe © 2019.”|
Take context into account. For instance, if the image above is part of a blog post about standing tables, then it’s safer to skip the part about standing tables.
Don’t start alt-texts with things like “Image of” or “Photo of.”. Screen readers add that by default. If it’s a special type of image (like an icon), you can note that at the end.
|“Image of a rocket.”||“A rocket.”|
|“Illustration of a rocket.”|
|Phoot of a rocket.”|
|“Icon of a rocket.”||“A rocket, icon.”|
End the alt-text with a period. This makes screen readers pause a bit after the last word in the alt-text, creating a natural pause before the next bit of text.
In most cases you should use an alt-text for images, but there are some exceptions where you should leave the alt-text blank.
If an image does not convey any meaning to the user, leave the alt-text blank.
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The rocket here doesn’t add meaningful information.
If an image has a label nearby, leave the alt-text blank.
TOP LEADERBOARD: 728X90
This ad unit is the most visible on the site.
The nearby text here already explains what the graphic illustrates. If there was alt-text here, screen readers would repeat information to the user.
alt="") will cause a screenreader to skip over the image. Never remove the alt-attribute. When a screenreader comes to an image without an alt attribute, it will dictate the filename (Eg. “SO underscore logo dot png”).
<img> tag, add the alt-text inside the
Inline SVG doesn’t support the
alt attribute, so instead add two wai-aria attributes: