SRT vs VTT: what changes when you convert?

SRT and WebVTT are text files that pair words with start and end times. They are not video files. You can open either in a text editor, but the application receiving your captions may ask for a particular format.

A small side-by-side example

This SRT cue shows a sentence from 1.2 seconds to 4 seconds:

1
00:00:01,200 --> 00:00:04,000
Every story starts with a little curiosity.

The corresponding WebVTT cue uses a file header and a full stop for milliseconds:

WEBVTT

00:00:01.200 --> 00:00:04.000
Every story starts with a little curiosity.

Changing an extension alone does not make that change. A converter needs to rewrite format-specific syntax while retaining the words and times.

Choose the format requested by your player

WebVTT is designed for web text tracks, including captions attached to HTML video. SRT is commonly exchanged as basic numbered subtitle cues. Use the format your target player or editor requests; conversion cannot add support to an application that does not accept a given format.

Watch for formatting loss

WebVTT supports cue settings, styles, voice annotations and word timing markers that have no direct equivalent in basic SRT. CueFern exports basic timing and text, retains basic bold, italic and underline, and warns about detected metadata loss. Keep the original file if advanced presentation matters.

Check a conversion before using it

1. Convert with SRT to VTT or VTT to SRT.
2. Compare several cues near the beginning, middle and end.
3. Open the exported file in your intended application and check line breaks and styling.

Format details are described in the W3C WebVTT specification. No converter can guarantee identical styling in every player.