January 16, 2022

Accessibility Standards: World Wide Web Consortium (W3C) Expands Work on Captions and Subtitles for More Accessible Video Content

From the World Wide Web Consortium (W3C):

The World Wide Web Consortium (W3C), the global standards organization that develops the foundational technologies for the Web, has published new global guidelines, TTML Profiles for Internet Media Subtitles and Captions 1.0 IMSC1 Recommendation, that will improve accessibility and make it easier and less expensive for distributors of online video content to deliver subtitles and closed captions worldwide.

“Previously, content creators and distributors used regional versions and variations of TTML captioning and subtitles so the viewing experience was inconsistent in different parts of the world,” said Philippe Le Hegaret, W3C Interaction Domain Leader. “Now, IMSC1 brings expanded new features, better technical quality, and consistency on a global scale.”

The harmonization of these technical guidelines for online video captions and subtitles was a collaborative effort among members of the W3C Timed Text Working Group, global experts and external organizations, including the European Broadcasting Union (EBU) and the Society of Motion Picture & Television Engineers (SMPTE).


An application of the W3C’s Emmy® award-winning Timed Text Markup Language (TTML), TTML Profiles for IMSC1 simplifies authoring and processing of subtitles and captions worldwide by harmonizing popular profiles of TTML, including EBU-TT-D, CFF-TT, SDP-US and SMPTE-TT.  In addition, W3C’s TTML Working Group updated the working draft of TTML 2, the second version of Timed Text Markup Language (TTML), which adds features introduced in IMSC1 as well as other improvements, such as additional support for East Asian language typography, stereoscopic presentations, and mapping to HTML and CSS.

Learn More, Read the Complete Announcement and Primary Document


About Gary Price

Gary Price (gprice@mediasourceinc.com) is a librarian, writer, consultant, and frequent conference speaker based in the Washington D.C. metro area. Before launching INFOdocket, Price and Shirl Kennedy were the founders and senior editors at ResourceShelf and DocuTicker for 10 years. From 2006-2009 he was Director of Online Information Services at Ask.com, and is currently a contributing editor at Search Engine Land.