Alt text

Not everyone can see images on web pages. “Alt text” is a text field associated with an image on a web page.

Alt text describes the image for people who can’t see the image but can read the text (including people who are blind and use screen reader software and people using technology that can’t load the images).

Even if the image isn’t critical to understand the web page, not knowing what’s in the image can leave you wondering if you’re missing something. An image’s alt text should emulate the experience of seeing the image as much as possible with reasonably brief text.

Alt text is different than a caption. A caption is text that is shown in addition to the image (not instead of it) and typically appears below an image (whether the image itself or its alt text is shown).

Writing effective alt text

  • Imagine you can’t see the image. What would you want to know to fill in the gap?
  • Keep it short – think tweet-length or shorter
  • Add information beyond the caption. People can also read the caption. The alt text replaces the visual of the image, not the caption below it.
  • Think key takeaways. You can’t describe everything, so what’s most important to understand?
  • Balance the literal with the significant. What’s the image showing that illustrates the point it’s making or the reason it’s in the story?
    • Too literal: “A blue house in the rain surrounded by trees with two people standing in front, a 42-year-old woman with brown hair and a 15-year-old teenage boy in a green shirt.”
    • Not literal enough: “Smith and her son say they are very happy here in spite of the weather.”
    • Balanced: “A middle-aged woman poses outside her house in the rain hugging her teenage son, both grinning at the camera.”
  • Trust your audience – you don’t need to shoehorn in more information than is actually in the photo.
    • Example: If the specific city or the date of the photo aren’t apparent from looking at it, then they probably don’t need to be in the alt text. (If that’s important information, the caption is a good place for it).
  • Stick to the visuals – in general, don’t go too far beyond what’s in the picture.
    • Example: unless someone’s a known politician, their name is probably better in the caption. Use the alt text to convey something visually important – what are they wearing? Where are they? Are they doing something important?

Examples

These are pulled somewhat randomly from recent stories on the web site.

The point is not that these alt text examples are brilliant writing (you can probably do better). These are just examples of what I come up with in one or two minutes on an image.

Two police officers approach a house with a Juneau police SUV parked in front.
Alt text: Two police officers next to a Juneau police SUV parked in front of a house.

Caption: Juneau police officers search a property in downtown Juneau after serving a search warrant on the property. (Photo by Tripp J Crouse/KTOO)

View of a hillside partially covered by evergreen trees with bare spots mostly higher on the hill.
Alt text: Distant view of a hillside partially covered by evergreen trees and vegetation with large patches of bare earth, mostly higher on the hill.

Caption: A clear-cut in the Tongass National Forest on Kupreanof Island in 2014. (Photo by Ed Schoenfeld/CoastAlaska)

Two smiling tourists walk beside train tracks adjacent to a docked cruise ship. A larger group of tourists and a train are in the background.
Alt text: Two smiling tourists walk beside train tracks adjacent to a docked cruise ship. A larger group of tourists and a train are in the background.

Caption: Cruise ships and passengers at Skagway’s railroad dock in May 2016. (Photo by Emily Files/KHNS)

A sandwich board sign on the sidewalk with the words "Vote here. Polling place here." An arrow on the sign points towards the front doors of the Douglas Library.
Alt text: A sandwich board sign on the sidewalk with the words “Vote here. Polling place here.” An arrow on the sign points towards the front doors of the Douglas Library.

Caption: The Douglas Library is normally one of more than a dozen polling locations for Juneau’s municipal election. During this year’s by-mail election, in-person voting will only be offered at City Hall and the Mendenhall Valley Public Library. (Photo by Rashah McChesney/KTOO)

Workers lined up along each side of a long table working on pieces of salmon in containers on the table. Workers are shown from the neck down and wear gloves and aprons.
Alt text: Workers lined up along each side of a long table working on pieces of salmon in containers on the table. Workers shown from the neck down, wearing gloves and aprons.

Caption: Workers remove the bones from salmon fillets at Alaska Glacier Seafoods’ Auke Bay processing plant in 2015. (Photo by David Purdy/KTOO)

Two young women pose for a picture sitting on the front bumper of a fire truck, wearing firefighters' uniforms and  holding helmets.
Alt text: Two young women pose for a picture sitting on the front bumper of a fire truck, wearing firefighters’ uniforms and holding helmets.

Caption: Two recent graduates of Capital City firefighter’s academy, Cat Pearson and Sadie Inman (photo courtesy of Sadie Inman, CCFR)