What Is TTML?

Direct definition

TTML (Timed Text Markup Language) is a W3C XML format for timed text. Streaming and broadcast pipelines often use a constrained profile such as IMSC rather than unrestricted TTML.

The sections below explain how TTML is used in transcription and subtitle work, what people often mix up, and which VideoText workflow applies when the next step is a file or review pass.

Key takeaways

• TTML is XML, not a numbered plain-text cue list.
• Ask which profile (IMSC, EBU-TT) a platform requires.
• VideoText’s browser tool can convert TTML to SRT; that is conversion, not a claim that VideoText authors native IMSC packages.

Why profiles exist

Full TTML is large. Netflix, IMSC, and EBU profiles limit features so players can interoperate. Delivering “a TTML file” without the profile name is incomplete.

Related terms

• WebVTT
• SRT file
• SCC
• All glossary terms

Sources

1. W3C: Timed Text Markup Language 2 (TTML2)