When you start working with subtitles seriously, you'll quickly discover there are multiple file formats — SRT, VTT, ASS, SBV, and more. For most creators, the choice comes down to two: SRT and VTT. Picking the wrong one means your captions silently fail to display.
What is an SRT file?
SRT (SubRip Text) is the oldest and most universally supported subtitle format. It contains numbered caption blocks, each with a start/end timestamp in HH:MM:SS,mmm format and caption text. Its simplicity is its superpower — SRT works on YouTube, Vimeo, Facebook, LinkedIn, Adobe Premiere, DaVinci Resolve, and virtually every video player in existence. When in doubt, use SRT. Capllio generates SRT by default for exactly this reason.
What is a VTT file?
VTT (Web Video Text Tracks) is the modern web standard for HTML5 video players. It's nearly identical to SRT but uses dots instead of commas in timestamps, and supports advanced features like text positioning, speaker identification, and styling cues. Use VTT when embedding video directly on a website using the HTML5 <track> element, or with streaming platforms using HLS or DASH delivery.
Which format should you use — by platform
- YouTube: SRT — native support, simple upload
- Vimeo: SRT or VTT — both work
- Facebook / Instagram: SRT — only supported format
- TikTok: SRT — only supported format
- LinkedIn: SRT
- Adobe Premiere Pro: SRT — imports directly to timeline
- DaVinci Resolve: SRT — use File → Import → Subtitles
- Final Cut Pro: SRT via third-party plugin or CEA-608
- HTML5 web video: VTT — use the <track> element
Capllio generates SRT files by default because they cover 95% of creator workflows. For VTT, a simple text rename and comma-to-dot substitution in the timestamps is all that's needed.