When you export subtitles, most tools offer at least two format choices: SRT and VTT. For a straightforward YouTube upload or LMS course page the difference rarely matters — both carry the same timestamp-and-text data and either will work. But the choice starts to matter when you're embedding video on a web page, delivering files to a broadcast workflow, or building a pipeline that touches several platforms. This article explains what each format is, how they differ in practice, and when to reach for one over the other.
What Is SRT?
SRT (SubRip Text) is one of the oldest and most widely supported subtitle formats. A file consists of numbered caption blocks, each containing a sequence number, a timestamp range in HH:MM:SS,MMM --> HH:MM:SS,MMM format, one or more lines of text, and a blank line as a separator:
1
00:00:02,500 --> 00:00:05,000
This is the first subtitle.
2
00:00:05,500 --> 00:00:08,200
And this is the second.SRT files are plain text, human-readable without any special tooling, and accepted by virtually every platform that handles subtitles: YouTube, Facebook, LinkedIn, Netflix, Premiere Pro, DaVinci Resolve, broadcast playout hardware, and almost every desktop and mobile video player. The trade-off for that universality is simplicity — SRT carries no styling information. Font, color, size, and screen position are all determined by the player, not the file.
What Is VTT?
VTT (WebVTT, or Web Video Text Tracks) was designed by the WHATWG as the native caption format for the HTML5 <track> element. The structure looks nearly identical to SRT with two key differences: a WEBVTT header line at the top of the file, and timestamps that use a dot instead of a comma as the millisecond separator (00:00:02.500 rather than 00:00:02,500):
WEBVTT
00:00:02.500 --> 00:00:05.000
This is the first subtitle.
00:00:05.500 --> 00:00:08.200
And this is the second.The meaningful difference from SRT is that VTT supports per-cue styling and positioning. You can specify caption placement with cue settings like line:, position:, and align:, or apply inline formatting with bold, italic, and CSS class tags. In practice, most players ignore the advanced cue settings and render captions at a default position. But for a web-based player you control directly, those options exist — and browsers parse them natively with no JavaScript library required.
SRT vs VTT: Side-by-Side
| SRT | VTT | |
|---|---|---|
Browser-native (<track> element) | No | Yes |
| Styling and positioning | None | Basic (cue settings) |
| YouTube | Yes | Yes |
| Vimeo | Yes | Yes |
| Udemy | Yes | Yes |
| Teachable | Yes | Yes |
| Premiere Pro / DaVinci Resolve | Yes | Partial |
| Broadcast / hardware playout | Yes | Rare |
| File size | Smaller | Slightly larger |
Most LMS and video platforms accept both formats interchangeably — Udemy and Teachable strip VTT's advanced features and treat the file as plain timed text. The practical differences surface at the edges: HTML5 web embeds and files going into broadcast software.
When to Use SRT
SRT is the right default in the majority of situations:
- Uploading to YouTube, Facebook, LinkedIn, or X — all accept SRT directly
- Delivering files to a post-production workflow in Premiere Pro, DaVinci Resolve, or Avid
- Sending to a client or third party where you can't verify their tooling
- Broadcast or hardware playout systems, which rarely support VTT
- Any case where you want the widest possible compatibility without worrying about edge cases
If you only have bandwidth to produce one format and aren't sure what the destination needs, SRT is almost never wrong. It's been around since the late 1990s and almost nothing rejects it.
When to Use VTT
VTT is the better choice in a few specific circumstances:
- Embedding video on a web page with the HTML5
<video><track>pattern — browsers handle VTT natively, no library required - Your LMS explicitly requires WebVTT (some platforms, particularly newer ones, specify this in their documentation — worth checking)
- You're using a JavaScript video player like Video.js, Plyr, or JW Player and want to use VTT cue settings for caption positioning
- You need per-caption inline formatting (bold, italic) that the player will actually honour
If you control the HTML and need caption placement, VTT is the right tool. For everything else, SRT covers the ground.
What If You Need Both?
Many projects end up needing both formats — SRT for YouTube and client deliverables, VTT for the course page or web embed. Converting between the two is mechanical: swap the comma for a dot in the timestamp millisecond separator and add the WEBVTT header line. But doing that manually for every video, in every language, on every project adds friction.
Capto exports SRT, VTT, TXT, and DOCX from the same transcript with one click. You generate the transcript once, then download whichever formats each destination requires. If you have translations, all four formats are available for each language from the same export panel — no re-transcription, no manual conversion.
The Bottom Line
For most upload workflows, SRT is the practical default: universal compatibility, no quirks, accepted everywhere. Reach for VTT when you're building a web player or when your platform specifically requires it. When your workflow spans multiple destinations, export both and let each platform use what it needs.
The harder part of subtitles is accuracy, not format. A clean, corrected transcript is the same raw material for either file — the format is just how you package it for delivery.