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Added Support for 4 New Subtitle Formats

By Edouard · February 23, 2026

We’re excited to announce that WebTranslateIt now supports four additional subtitle formats, making it easier than ever to localize your video content for global audiences.

Why Subtitle Localization Matters

Video content is exploding across platforms—from YouTube and streaming services to corporate training and e-learning. But video without localized subtitles leaves a significant portion of your audience behind. Studies show that:

  • 80% of viewers are more likely to watch a video to completion when subtitles are available
  • Subtitles improve comprehension even for native speakers
  • Localized subtitles dramatically increase engagement in international markets

With these new formats, WebTranslateIt now supports the most widely-used subtitle standards across web, broadcast, and entertainment industries.

New Formats

WebVTT (.vtt)

WebVTT (Web Video Text Tracks) is the native subtitle format for HTML5 video and the standard for modern web browsers. If you’re publishing video content on the web, chances are you need WebVTT.

Key features we support:

  • WEBVTT header with optional descriptions
  • STYLE blocks for CSS-based styling
  • REGION blocks for precise positioning
  • NOTE blocks for translator comments
  • Cue identifiers and settings (position, line, align, vertical)

SAMI (.smi, .sami)

SAMI (Synchronized Accessible Media Interchange) is Microsoft’s caption format, commonly used in Windows Media Player and corporate environments.

What makes SAMI unique:

  • HTML-like structure that’s familiar to web developers
  • Built-in multi-language support via CSS classes
  • Rich styling through embedded CSS
  • Timestamps in milliseconds for precise sync

ASS/SSA (.ass, .ssa)

Advanced SubStation Alpha is the format of choice for anime fan-subbing and any video requiring advanced typography. If you’ve ever seen subtitles with custom fonts, colors, or karaoke effects, it was probably ASS.

Powerful features:

  • Multiple named styles with full font control
  • Precise positioning and rotation
  • Override tags for inline formatting
  • Layer support for complex compositions
  • Effects and animations

TTML/DFXP (.ttml, .dfxp)

TTML (Timed Text Markup Language) is a W3C standard widely used in broadcast television and streaming services like Netflix and Amazon Prime Video. DFXP (Distribution Format Exchange Profile) is a subset of TTML.

Enterprise-grade features:

  • Well-formed XML structure
  • Reusable styles and regions
  • Flexible timing with begin, end, or duration
  • Extensive positioning and layout control
  • Strong industry adoption

How to Get Started

Translating these formats in WebTranslateIt is straightforward:

  1. Upload your source subtitle file in the File Manager
  2. Translate using our Translation Interface
  3. Download the localized file in the same format

All our translation tools work seamlessly with these formats:

Complete Subtitle Format Support

With these additions, WebTranslateIt now supports 8 subtitle formats:

Format Extensions Best For
SubRip .srt Universal compatibility
YouTube .sbv YouTube uploads
WebVTT .vtt HTML5 video, web browsers
SAMI .smi, .sami Windows Media, corporate
ASS/SSA .ass, .ssa Anime, advanced styling
TTML/DFXP .ttml, .dfxp Broadcast, streaming services
MicroDVD .sub Legacy media players
SubViewer .sub Media players

Start Localizing Today

Whether you’re subtitling a YouTube series, preparing content for Netflix, or creating accessible corporate training videos, WebTranslateIt has you covered.

Create a free account and upload your first subtitle file today.


Questions about subtitle localization? Contact our support team—we’re happy to help.