Checkpoint 7.1.2 Captioning Synchronization

Where ICT displays captions, the mechanism to display captions shall preserve synchronization between the audio and the corresponding captions.


The European standard specifies requirements for caption processing technologies. These need only be addressed for software applications that are media players or contain embedded players. Other applications should mark this N/A (not applicable).

Refer to Requirement 7.1.2: Captioning synchronization for more information (external link to EN 301 549 toolkit).

Note: Several “Time-based Media” Success Criteria in WCAG 2.0, such as 1.2.2 Captions (Prerecorded), require that captions are provided. Those stipulate that when creating content, the author must ensure audio content has been transcribed and is captured in a format that can be used to provide synchronized captions. Those requirements covering the content of the captions are complementary to chapter 7 of EN 301 594, which covers the actual process of displaying closed captions during playback, including ensuring the media player provides the captions in such as way that they are synchronized with the audio content for which they provide an alternative.

Note for IBM teams: The IBM compliance reporting system will be able to convey compliance status with European EN 301 549/Mandate 376: Accessibility requirements suitable for public procurement of ICT products and services in Europe. Revised Section 508 checkpoints cover most of the EN 301 549 requirements. However, this is one of several additional checkpoints that will need to be completed to fully report compliance with the European standard.

Development Techniques

Note: Review the General techniques as well as other tabs applicable to your technology.  Prioritize the use of technology-specific techniques, and implement the General techniques as needed. You are always required to find, understand and implement accessible code techniques to meet the checkpoint. The documented techniques and supplements are not exhaustive; they illustrate acceptable ways to achieve the spirit of the checkpoint. If numbered, techniques are in order of preference, with recommended techniques listed first.

General techniques

There are currently no related techniques.

Note: open captions are considered to always meet 7.1.2, since they are permanently burnt into the video, and so cannot have the synchronization affected by the media player.

Mobile Native (iOS) techniques

There are no specific Mobile Native techniques for this checkpoint. Refer to the General techniques section.

Eclipse techniques

There are no specific Eclipse techniques for this checkpoint. Refer to the General techniques section.

Windows-based (MSAA+IA2) techniques

There are no specific Windows-based (MSAA+IA2) techniques for this checkpoint. Refer to the General techniques section.

Many links in this checklist reside outside at the Web Content Accessibility Guidelines (WCAG) 2.1. W3C Recommendation 05 June 2018:

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