SRT
SRT is one of the most widely recognised subtitle formats.
It stores a sequence of subtitle events with start and end times and text content. Its simplicity makes it useful for many editing, online and exchange workflows.
That simplicity is also a limitation. More complex positioning, styling or accessibility requirements may need a richer format or a platform-specific specification.
An SRT should therefore not be selected automatically merely because it is familiar.
WebVTT
WebVTT is a timed-text format designed for use with web media.
The W3C specification defines it for external text tracks associated with audio and video, including subtitles and captions. It can also support other kinds of time-aligned text data.
WebVTT is common in browser-based and online video environments.
A client using a web player should still confirm what that player expects, as implementation and feature support can vary.
STL
STL is associated with professional subtitling and broadcast workflows.
There are different uses of the letters STL in audiovisual environments, so the exact expected format should be confirmed rather than inferred from the extension alone.
When a broadcaster or post-production supplier requests STL, we ask for the relevant technical specification or a valid reference file where necessary.
TTML
TTML is an XML-based timed-text family used in professional media workflows and can support more structured presentation information than simple text formats.
Platforms and broadcasters may use particular TTML profiles rather than a completely generic implementation.
For this reason, delivery should follow the recipient’s actual specification.
SCC
SCC is used in captioning and broadcast-related workflows, particularly in North American environments.
It may be requested for caption deliverables where timing and caption data need to conform to a specific technical chain.
As with other professional formats, the receiving system’s requirements should define the final file.
Subtitle files versus burned-in subtitles
A timed subtitle file is separate from the video and can often be activated or disabled by the viewer or platform.
Burned-in or open subtitles are rendered permanently into the picture.
These are different deliverables.
If a client needs the text embedded into the final video rather than supplied as a timed file, the video format, resolution, encoding and visual requirements should be assessed before quotation.
Closed and selectable tracks
A platform may allow viewers to choose between several subtitle or caption tracks.
This is common in multilingual distribution because the same video file can be accompanied by separate timed-text resources for Spanish, Basque, Catalan, English and other languages.
The player or platform determines how those tracks must be packaged and labelled.
Timing data
Converting between formats is not only about changing a file extension.
Frame rate, timecode conventions, cue settings, styling support and metadata can affect whether information is preserved correctly.
A conversion should therefore be checked against the destination requirements, particularly in professional broadcast or platform workflows.
Styling and positioning
Simple formats may offer little control over where and how subtitles appear.
Other timed-text formats can carry richer presentation information, but the receiving platform may restrict or reinterpret those features.
When precise positioning, speaker placement or accessibility styling matters, the destination specification should be known before final delivery.
Character encoding and scripts
Multilingual files can contain Latin, Cyrillic, Arabic, Chinese, Japanese, Korean and other scripts.
The workflow needs to preserve the required characters correctly throughout translation, export and import.
A file that looks correct in one editor can still fail if another system interprets encoding or unsupported glyphs differently.
We therefore include file integrity and character handling among the technical checks appropriate to the project.
File naming and multilingual deliveries
Large localisation projects may contain many language files for the same video.
A clear naming convention reduces errors and helps the client’s production team identify source, target language, version and asset.
Where the client already has a naming standard, we can follow it. Otherwise, the required naming and folder structure should be agreed before a large batch is delivered.
Which format should I request?
Start with the destination rather than the format name.
Tell us whether the subtitles are for a website, LMS, broadcaster, festival, editing system, streaming platform or another workflow.
If the recipient has supplied a technical specification, send it with the project.
This is more reliable than choosing a format first and trying to make the delivery system accept it later.
Frequently asked questions
Is SRT always the best subtitle format?
No. SRT is simple and widely supported, but some workflows require styling, metadata or caption features that are better handled by another format.
What is WebVTT used for?
WebVTT is designed for timed text associated with web media and can carry subtitles or captions.
Can you convert subtitle files between formats?
Yes, where the source and target formats make that conversion appropriate. Features that are not supported by the target format may need special handling.
Can you deliver several language files for the same video?
Yes. We can coordinate multilingual subtitle packages and follow the client’s required naming structure.
Can you provide burned-in subtitles?
We can assess projects requiring text embedded into the picture. Video specifications need to be known before confirming the deliverable.
Which format do I need for captions?
That depends on the target platform or broadcaster. SCC, WebVTT, TTML and other formats can be used in different captioning environments.