If you work with subtitles — for YouTube videos, films, courses, or corporate content — you’ll run into two file formats again and again: SRT and VTT. They look almost identical at first glance, but they behave differently, and picking the wrong one can mean a player that silently refuses to show your captions.

Here’s what actually matters about each.

What is an SRT file?

SRT (SubRip Text) is the oldest and most widely supported subtitle format. It was originally created by the SubRip software in the early 2000s and has been the de facto standard ever since.

An SRT file is plain text with a simple repeating structure: a sequence number, a timecode line, and the subtitle text.

1
00:00:01,000 --> 00:00:04,000
Hello, and welcome to the video.

2
00:00:04,500 --> 00:00:07,200
Today we're talking about subtitles.

Two details to notice:

The timecode separator is a comma (00:00:01,000)
Every cue starts with a sequence number

SRT supports almost no styling. Some players honor basic tags like <i> and <b>, but that’s it. What it lacks in features it makes up for in compatibility: VLC, Plex, YouTube, Premiere Pro, DaVinci Resolve, smart TVs — practically everything reads SRT.

What is a VTT file?

VTT (WebVTT, “Web Video Text Tracks”) is the web-native subtitle format, standardized by the W3C for HTML5 video. If you’re adding captions to a <video> element with a <track> tag, the browser expects VTT — SRT will not work.

WEBVTT

1
00:00:01.000 --> 00:00:04.000
Hello, and welcome to the video.

2
00:00:04.500 --> 00:00:07.200
Today we're talking about subtitles.

The differences from SRT are small but strict:

The file must begin with the header line WEBVTT
The timecode separator is a period (00:00:01.000), not a comma
Sequence numbers are optional
VTT supports richer features: cue positioning, colors, per-speaker styling with CSS, and metadata notes

So which one should you use?

The short answer: let the destination decide.

Destination	Format
HTML5 video on a website	VTT (required)
YouTube, Vimeo uploads	Either works (SRT is the safe default)
VLC, Plex, media players	SRT
Video editors (Premiere, Resolve)	SRT
Course platforms (Udemy, Coursera)	Usually VTT

If you’re distributing a file for others to use and don’t know their player, SRT is the safer bet purely on compatibility.

Converting between SRT and VTT

Because the formats are so close, conversion is mechanical: add or remove the WEBVTT header and swap commas and periods in the timecodes. But doing it by hand in a text editor is error-prone — one missed comma and some players reject the entire file without an error message.

Our free SRT ↔ VTT converter does it instantly in your browser. No signup, no upload to a server — the file never leaves your machine.

Translating subtitle files

One more thing the formats have in common: translating them is painful by hand, because you have to preserve every timecode and cue boundary while replacing only the text. Paste a subtitle file into a generic translator and it will usually mangle the structure.

That’s exactly what our free subtitle translator is built for — it parses the SRT or VTT structure, translates only the dialogue into any of 50+ languages, and gives you back a valid subtitle file with the original timing intact.

TL;DR

SRT: oldest, simplest, works almost everywhere. Comma in timecodes.
VTT: web standard, required for HTML5 video, supports styling. Period in timecodes, WEBVTT header.
They’re 95% the same — convert between them freely and pick whichever your platform expects.