Adding accessible captions to YouTube Movies

Ben Logan  | 

Video is a key component of an internet presence and sites such as YouTube and Vimeo offer to host video for no additional cost. High bandwidth sites would have previously incurred significant charges for streamed video but now any site owner can frequently publish their video content online for no extra cost.

Why caption videos?

Multimedia presentations (rich media) usually involves image, sound and motion. This can present accessibility barriers to some people with disabilities, for instance visual impairments, hearing loss, photosensitive epilepsy, cognitive and learning disabilities, attention deficit disorder, and dyslexia.
Captions and subtitles make videos accessible to a wider audience by allowing folks who cannot otherwise understand the audio track to follow along.

Which Web content Accessibility Guidelines 2.0 checkpoint does this address?

1.2.2 Captions(Prerecorded): Captions are provided for all pre-recorded audio content in synchronized media, except when the media is a media alternative for text and is clearly labelled as such. (Level A).

Getting started

We are going to go through the process of taking a video and adding some captions so you will need the following to get started.

  • Video file – we are using a .mov file from a Mac testing session using
  • YouTube account
  • Internet Access to CaptionTube
  • Headphones

1. Upload the video

The first thing we did was to upload a video to our existing area on YouTube.

Screenshot of Video upload on YouTube

2. Login to CaptionTube

We then logged into CaptionTube and were presented with two options. The first option was for “Personal video” if the video has already been uploaded to YouTube and the second option is “Specific Video” if you know the URL of the video but did not upload it yourself. As we have already uploaded a video we went for the first option.

Screenshot of options in CaptionTube

3. Authorise access to your account

Once we selected the “Personal Video” option on CaptionTube we were presented with a button on the site that read “Go to YouTube”, which we needed to press in order to grant CaptionTube access to access our videos on YouTube.

Screenshot of authorising access to CaptionTube

We were then taken to YouTube and given the option to allow CaptionTube access to our account by pressing the “Allow Access” button.
The next screen showed us the available videos to import from our account on YouTube and we selected the radio button next to the only item in our list, which in this case was called “SpotlessTest BBC test 20091109”. Following this we then pressed the “Import” button. After a brief pause the video was then available for editing, and we pressed the “Edit” button.

Screenshot of available videos to import from YouTube

3. Adding captions in CaptionTube

We were then presented with the screen to add Captions. The video appears in a window on the left of the screen, with the same dimensions and parameters as a standard YouTube video, and the timeline controls and area to add captions appear to the right of the video on screen.

Screenshot of caption area in CaptionTube

We pressed the “Add Caption” button on the screen which then highlighted the caption start time, and also allowed us to enter text into the text box at the chosen time. In this case we wanted to add a caption right at the start of the video at “00:00:00.000” and we entered the following text “This is a demonstration of how you can easily add captions to YouTube videos”. The next step was to press the “Save Caption” button.

Screenshot of adding caption in CaptionTube

The timeline in the bottom left hand area of the screen is now coloured purple at the start of the video to indicate a chunk of captions added at this time code. This is very similar to how video editing tools and music sequencers work. There are options to zoom in and show more of the timeline with the slider control on the bottom left hand of the page.

Screenshot of timeline in CaptionTube

4. Working with the timeline in CaptionTube

We repeated the process of adding captions by dragging the timeline to where we wanted the caption to appear in the video and adding the relevant text. There is also a preview option within CaptionTube so you can preview the timings of the captions before you export them.

When the video is playing it can be quite tricky to add additional captions in the right place so we found ourselves pausing the video as we went through to make sure the caption appeared the right place each time. This took a bit of getting used to, but as a free hosted tool we found this to be quite effective.

Screenshot of preview option in CaptionTube

5. Exporting captions in captionTube

CaptionTube can export in two different formats either the SubViewer format (.sub) or SubRip format (.srt). We followed the default option which was the SubRip format (.srt) and left the first radio button checked for “Download the captions as a file.” and pressed the “Download Now” button. We saved the caption file off to the desktop.

Screenshot of caption export options in CaptionTube

6. Associating caption file with video

The final step is in the process is to associate the caption file exported from CaptionTube with the video within YouTube. At this stage I am not sure why the process is not linked through the site e.g. you can associate the caption with the video from CaptionTube and it posts back this information to YouTube. I can only guess there is some privacy reason as to why this is not currently the case?

Once logged in I navigated to the following area in YouTube: My Account > Uploaded Videos > Selected the video then > Captions. I was then able to browse to the caption file on the desktop and upload this after selecting English as the language.

Screenshot of upload caption file in YouTube

7. Viewing captions in video

You can now watch the video with the captions running by selecting the icon in the far right hand corner and turning on the captions.

Screenshot of captions working in YouTube

Visit the Spotless Interactive captioned Video on YouTube.


At the time of writing this YouTube is one of the main sites that offers this facility. Sites such as Vimeo do not currently offer caption support for video but this is something they will address going forwards.

Got a project in mind?

Danny, our Client Services Director, is on hand to answer your questions.

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