How to make video and audio accessible

Captions for video

Add captions to videos that are pre-recorded or live, and make them closed captions, not open.

Captions provide a text alternative to spoken dialogue. They also include non-dialogue audio information needed to understand the content like sound effects, music, laughter, speaker identification and location.

Captions help people who:

are in noisy environments or want sound off in quiet places
find reading text easier than listening to audio
are Deaf or have a hearing impairment

You must provide captions for pre-recorded and live video to make it accessible.

Types of captions

There are two types of captions:

Closed captions can be turned on or off by the user and are supported by most media players.
Open captions are 'burned-in' and cannot be turned off by the user - they're always on.

Closed captions

Closed captions are better for accessibility because people can to turn them on or off. Some video players, like YouTube, also allow people to customise the appearance of closed captions.

Closed captions are added to your video after it's been created.

Use closed captions when possible.

Open captions

Open captions give people no choice since they are always on screen. They also duplicate content on channels that support automatic closed captioning.

Avoid adding open captions to videos in most cases, use closed captions instead.

Open captions may still be used on channels that do not support closed captioning, like some social media channels.

Be sure open captions:

have good colour contrast so people can read them
do not block important visual information in the video

Open captions are built into your video when it's being created. You may need to create a separate open caption video if you plan to use it on channels that do not support closed captions.

When to use captions

Pre-recorded videos with informative audio must have captions. This includes:

speech
sounds that give video content important meaning, like laughter
sounds indicating something happening off-screen

They do not need captions if they do not have audio or have audio, but it's background audio.

If your video does not need captions, add text to the video description or close to where it's embedded on a webpage explaining why. For example, 'No captions provided as the video's audio does not add meaning'.

Videos with no audio, but with important messaging like visible text are unlikely to be accessible unless they are given an audio description.

Live video streams also need captions. Streaming services like YouTube allow you to add live auto-captioning to your stream during setup.

How to write good captions

The main purpose of captions is to provide information that you hear to people who cannot hear the audio. Your captions must accurately reflect the video audio.

This means they must:

include all speech
include all important sounds [in brackets]
have accurate spelling and punctuation
be visible for at least one second
appear roughly at the same time as the audio
not hide any important visuals

Captions must also indicate a change of speaker if either the:

identity of the speaker impacts the meaning of the audio
visuals don't show who's speaking, like an interviewer asking a question off camera

For example, read the closed captions in these Screen reader demonstration videos from RNIB.

Auto-generated captions

Some hosting sites, like YouTube, add captions to videos automatically.

Auto-generated captions are a good starting point, but you must check and edit the captions to make them accurate and complete.

How to add captions to pre-recorded YouTube videos

On our YouTube channel, the easiest way to make videos captions is to use the these steps:

Create a script with a visual description of what's happening on screen and use this to narrate or audio describe the video.
Request the audio described video be uploaded to our YouTube channel.
Request a text file of the automatic captions YouTube generates (with time stamps included).
Check the auto-captions are accurate, fix any errors and add information that's needed, like change of speaker or important sounds.
Send the updated text file (with time stamps) back to us so we can update your video.

Captions, subtitles and transcripts

Captions are not the same as subtitles or video transcripts. Subtitles translate spoken dialogue from a different language.

Video transcripts are a separate text version of speech and non-speech audio information and include visual information needed to understand the content.

More about captions

Web Content Accessibility Guidelines

This guidance may address the following: