Accessible images, audio and video

A basic rule when it comes to images, audio and video in digital channels is that there must be an alternative way of being able to get access to the meaningful content. One common way is to use text, for example alternative texts or subtitling.

Images on the web

Alternative text to images

In most content management tools, you can add descriptive texts, so-called alternative texts or alt texts, when uploading an image. Please remember that alternative texts fill a different function to image captions. Unlike image captions, alternative texts are intended for people who cannot see the image. This is why you must not simply copy the image caption and use that as an alternative text, but instead, you should write the alternative text so that it helps someone who cannot see the image.

Some advice for writing descriptive alternative texts

  • Be short and to the point.
  • Describe the image, for instance: "Two people sat on a couch."
  • Mention if the image is a photo or an illustration.
  • If you are adding the name of the photographer, please do so last.
  • Always finish off the alternative text with a full stop.
  • Images that are only added decoratively, for instance a line, do not need alternative texts.

Avoid using images that contain text

Screen reading software cannot decipher text that is encapsulated in an image. Instead, type the text on the page. If the image requires a long explanation, you can either type the explanation on the page where the image is found, or set up a separate page that you link to.

Accessible video


Captions of a video must represent the dialogue and other important sounds, for instance a telephone ringing. The dialogue must not be typed down word-for-word, but can be shortened to the most important information. Audio descriptions are often added in square brackets, [...], to separate them from the dialogue.

When ordering a video from the university's Inhousebyrån, captions in the original language is always included. If you order video from another supplier, you must remember to add captions and/or subtitles to your order.

At Umeå University, UmU Play, Vimeo and YouTube are used to publish videos. All these services support captions and subtitles. If you use other video services, you must use captioning functionality as far as possible.

Terminology: "captions" is a written transcription in the same language as the language spoken, whereas "subtitling" is a written translation of speech spoken in a different language.

Audio description

All key visual elements in a recording must be understandable through audio. This could be accomplished using dialogue, voice-over speaker, background sounds and other audible parts of the original sounds, or a separately recorded voice – audio descriptions – that expresses any visual content.

Live broadcast

There are tools to caption live broadcasts in real-time, but this is not a legal requirement. Live broadcasts must, however, be captioned and be made accessible if the content is accessible after the live event.

Audio files

If a recording only consists of audio, for instance a podcast, you must offer an alternative way for the visitor to access the content. This could, for instance, be through a text-based manuscript or a transcription.

Jonas Mattebo