What Is an SRT File? SRT vs VTT Explained

A small example you can read at a glance

Here is what a tiny SRT file looks like. Each block is a number, a time range and one or two lines of text, followed by an empty line:

1
00:00:01,000 --> 00:00:03,500
Welcome to the channel.

2
00:00:03,600 --> 00:00:06,000
Today we are making subtitles.

The time before the arrow is when the line appears, and the time after it is when the line disappears. Times are written as hours, minutes, seconds and milliseconds, with a comma before the milliseconds in SRT.

Why SRT became the standard

SRT is simple, human-readable and has no required styling, which is exactly why almost every tool supports it. YouTube, Vimeo, Facebook, LinkedIn, video editors, media players and many TV and streaming workflows can read it. If you only keep one subtitle file, SRT is the safest one.

Because it is plain text, you can fix a typo with any text editor, compare two versions to see what changed, or search for a word across many files at once.

When VTT is the better choice

• You are adding subtitles to HTML5 video on your own website; web players are built around VTT.
• You want extra features such as positioning or basic styling that VTT supports.
• You are building an accessible web page and want to follow current web conventions.

The first line of a VTT file is the word WEBVTT, and the milliseconds use a dot instead of a comma. If you ever convert by hand, those two changes are the main differences.

Common problems and how to avoid them

• Broken characters. Save the file as UTF-8 so accents, symbols and non-Latin scripts display correctly.
• Subtitles out of sync. Make sure the subtitles were created from the final version of the video; trimming afterwards shifts the timing.
• Overlapping times. A line should end before the next begins, or players may show two lines at once.
• Missing blank lines. Each block needs an empty line after it; without it, many players cannot read the file.

Our generator writes valid files in both formats, so these problems rarely appear unless a file is edited by hand. To put the file to use, see adding subtitles to a YouTube video or using an SRT file in Premiere Pro or DaVinci Resolve.