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Accessibility of videos (e.g. online lecture recordings)

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For a video to be accessible, you must understand its message just by listening or just by seeing the image and captions.

As a rule of thumb, the point of an accessible video presentation can be determined by listening or watching only. Making a video with an audio track that works independently often requires planning or at least practice. It can help if the person performing in the video thinks they are recording a radio programme/podcast.

You should consider accessibility already when designing your video so that you are prepared for the requirements in advance: making a script provides a good tool for ensuring accessibility.

Please note that even if you do not record your lecture, you can use this guide to improve the accessibility of your lecture.

The University of Oulu and the Oulu University of Applied Sciences must comply with the accessibility requirements under the Digital Services Act, so consider the following in the case of videos:

  1. Visual accessibility because the message of an accessible video must be clear to the viewer even without any sound.
  1. Audio accessibility because the message of an accessible video must be clear to the viewer even without any picture.
    • The audio track alone should convey all the essential information in the video, i.e., the spoken words should be descriptive of the visual material.

There are also exceptions to accessibility requirements. These are listed in the section about subtitling the videos. You should try to comply with the accessibility requirements even when it is not required by the law – at least where it is easy to do.

1. Visual accessibility: accessible presentation materials

If you create your presentation material in PowerPoint format, for example, and share it with students through screen sharing, the following tips will help make the presentation more accessible.

1.1 Make sure your presentation materials are easy to perceive for diverse people

  1. Ensure sufficient contrast between the text or visual objects and background. You can test colour combinations using, for example, the WebAIM Contrast Checker service: the minimum target level is WCAG AA. If you use a predefined template, make sure it meets the accessibility requirements. (Communication professionals have drawn up the University of Oulu and Oamk templates, so using them as such, without changing the colours, should ensure that contrast requirements are met.)
  2. Do not fill PowerPoint slides with text. There are no strict rules for this, but when using text in your slides, the text size should preferably be at least 30 pt.
  3. For a presentation that will be recorded, leave a blank space at the bottom of the slide for possible captions.
  4. If you use graphs in your slides, consider the colour blinds. To do this, you can try to print a black-and-white PDF from your PowerPoint (via the Print menu; print to file) and then check that the graph lines/bars/sectors stand out from each other. Also, for image files, you could use a tool on your computer that mimics colour-blindness, such as Coblis — Color Blindness Simulator.
    • When choosing the colours for graphs, make sure that the lines, bars and sectors stand out sufficiently from the background: check the colours in the graphic elements section of the WebAIM Contrast Checker service. For bars and sectors, you can solve the issue by using a border line that provides sufficient contrast with the background.
  5. Do not use colour alone to convey information. For example, if you are using a pie chart, indicate the sectors with text, for example. Colour is good in supporting the communication of information, but it must not be the only method. Different line types and fill patterns provide another option. They can be supported by colour choices as long as the colours stand out sufficiently from the background (see the above item in this list).
  6. If your online lecture is to be recorded and used for a longer period of time, you should describe out loud any images you show when giving the lecture: when you say out loud the essential things that appear in the image, the information is also passed on to users who cannot see the image well or at all. (You can imagine that you are making a podcast or radio broadcast.) In fact, this is how you can make your lecture accessible on the spot, as there might be someone in the audience, who is not able to see what you are showing. So doing this can always be recommended.

If you provide the presentation material to the participants in the form of a PowerPoint file, ensure that it is an accessible PowerPoint file. You should also consider the option that, instead of a PowerPoint file, you could provide the presentation to the participants as a written summary in the form of, for example, an accessible Word file. In this case, you can better focus on preparing the actual presentation material on the terms of the presentation, only needing to ensure that it is visually accessible.

PowerPoints doubling as lecture and presentation material are often quite text-heavy. A more visual PowerPoint intended as presentation material contains more images, graphs, keywords, etc., rather than complete sentences/text paragraphs that are well-suited to be used in a written summary of the lecture.

Screen capture videos

When making a screen capture video to create, for example, an instructional video on how to use a program, you should limit the capture area to the part that is needed. To do this, you can use zooming or a crop tool if the recording application you use has one. (See, e.g. Adjusting Screen Capture Settings –( By limiting the capture area, any text and elements on the video will show as big as possible. However, remember to leave room for captions at the bottom of the video. If necessary, you can also adjust the mouse pointer and cursor size. See, e.g. Make your mouse, keyboard, and other input devices easier to use (

1.2 The video must not cause a seizure or physical reaction

An accessible video must not contain flashing above the threshold value (3 times/s) because a rapidly flashing element may trigger an epileptic seizure or migraine in some people.

If the video requires showing an essential phenomenon with flashing above the threshold, it must be clearly stated at the beginning of the video that watching it may cause a seizure or physical reaction. It is also important to understand that the video cannot, in this case, be accessible.

1.3 Captioning videos

If a video must be accessible, it must have captions. (See Captions: How to Meet WCAG AA-level ( NB. The law does not require captions for live streaming).  These are our three categories of caption quality:

  1. High quality: Professional captioning, which follows e. g. the Netflix style guide: English Timed Text Style Guide ( High quality captions are recommended for videos intended for a wide audience and long lifespan. This level can be expected only from professional text workers. For example projects that produce high quality videos, should have captioning in their budgets.
  2. Acceptable quality: automatic captions, which are revised and corrected, are adequate for most of the videos. The main objective is to make sure the content is correct and it matches the audio. The captions can be colloquial. Captions in acceptable quality is a minimum requirement for videos that must be accessible. The maker/owner of the video is responsible for the captions.
  3. Unverified automatic captions: Videos that don’t have to be accessible, should still be captioned automatically, whenever possible. While unverified captions will not make a video accessible, it’s still better than nothing. However, please make sure the users know if you are providing unchecked automatic captions, as it is possible there are some serious errors. Read more about automatic captions.

Which videos should be accessible, how to make captions and other relevant remarks:

  1. The University of Oulu and Oamk use the YuJa media management system, which also features automatic captioning in Finnish and the option to correct the captioning afterwards. (See captioning videos in Yuja)
  2. The law requires videos that are used for more than 14 days to have captions. (= Captioning should be made within 2 weeks.)
    • Note: if the video falls under the accessibility requirements and can be considered to be useful after 14 days, and the video cannot be captioned, deleting the video is not a solution in the spirit of the law: the spirit of the law is to promote accessibility. (Also, see disproportionate burden.)
  3. There is no need to subtitle live broadcasts.
  4. If the videos are used only for a limited group for the duration of a single course implementation (= the use is not continuous), the videos would not need to be captioned based on the law. Still, you should at least include the option of auto-captions in these cases as well. In YuJa, the owner of the video can request auto-captions for their video. However, there are still a lot of quality problems with Finnish speech.
    • If your video ends up being used for a longer period of time, the recommendations will become requirements. Long-term use also includes using the same video for several course implementations.
  5. If your video is a media alternative for text, it does not need captions. In this case, you offer the same information as a web page/file, and the video is just one alternative method used to convey the same information. (Besides a video, a media alternative for text can be an audio file. The video may be silent or a regular video with an audio track.)
    • The content of the website/file and the media alternative provided with it must be the same, i.e., whether you choose to watch the video or read the text, they must convey the same information, no more and no less.
    • When a video is used as a media alternative, it must also be clearly labelled as a media alternative for text.
    • Media alternative increases accessibility because, for some people, video as an alternative presentation method may be easier to understand than text.
  6. Old videos published before 23 September 2020 do not need captions. Still, the same thing applies to them as to all recordings in YuJa: the owner of the video can request auto-captions for them.
  7. Note that auto-captioning is not a ‘silver bullet’ to solve all problems because the quality of the captions can vary. The quality may be very good, but there is often at least something to fix, also. If there is a lot to correct, it can be due to a poor-quality microphone, simultaneous speech, unclear/fast speech or difficult terminology and the simultaneous use of several languages at the same event.
    • Automatic captioning makes mistakes. Therefore, it is important to check automatic captions and edit any words that are transcribed incorrectly. Errors must be corrected manually. Unreviewed automatic text is not necessarily accessible. Accessible captions convey the video message to the viewer without errors. Still, even unreviewed captions (of mostly good quality) are more accessible than if there were no captions at all. However, the viewer should, in this case, be clearly informed that the captions have been made automatically and have not been reviewed, meaning that there may be errors. In this case, it must also be recognised that the video is not, in fact, accessible.
  8. If auto-captions do not produce sufficient quality, and editing would imply an unreasonable burden, deleting the video is no solution.

Manual corrections to the content of accessible captions

The captions should convey everything that is essential in the audio track.

  • The essential content of the speech must be conveyed, but fillers and stammers irrelevant to the understanding of the content can be removed.
  • Other relevant sounds should be indicated in the captions, so any beeps, laughter and applauding should be included in brackets, e.g. (beep)
  • If the speaker changes in midstream and it cannot be deduced from the video visually, the change must be indicated in the captions, e.g. (Teacher:) or (John:).
  • The language of accessible captions is always the same as the language spoken in the video. If you need the video to be accessible in two languages, it makes sense to prepare two versions of the video with identical content in the required languages.

Captioning videos in Yuja

Auto-captioning means that the program uses voice recognition to create captions in the language spoken in the video. Therefore, auto-captions are not the same as translated subtitles. The accessibility requirements explicitly require an alternative presentation of speech, i.e. the captions are in the same language as the speech on the audio track.

Log in to YuJa first. (How to log in to YuJa using a browser)

  • Requesting auto-captions for videos in YuJa:
    Requesting auto-captions (
    When requesting captions in YuJa, select the main language spoken in the video as the desired language. (Also, note that auto-captioning is limited to one language per video. If two languages are spoken in turn in the video, you can create auto-captions for both languages separately and then manually compile a single file of them using a word processing program. However, it can take a lot of work if the language changes frequently. When the captions are ready, you can upload them to YuJa. You can find the related instructions in this list.
  • The quality of auto-captioning will improve with use: the artificial intelligence behind auto-captioning learns from the improvements and corrections made to the videos. In addition, you can use the custom dictionary in YuJa (Auto-Captioning Dictionary ( that artificial intelligence strives to use to recognise special terminology and names.
  • Editing video captions in the YuJa video editor:
    Editing captions in the YuJa video editor (
  • You can also download the video caption file (.srt) to your computer for editing:
    Downloading captions ( This way, you can edit the captions in WordPad or using the dedicated Subtitle Edit program (open source). For the staff, Subtitle Edit is available through the Software Center.
  • Exporting the edited captions back to YuJa:
    Manually uploading captions (

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