Paste or upload an SRT file and convert it to WebVTT with the required header and web-ready timestamps, ready to download.
HTML5 video uses WebVTT for its track element, while many editing tools and download sites supply SRT. The two formats differ in three practical ways: WebVTT must begin with a WEBVTT header line, its timestamps use a dot before the milliseconds instead of a comma, and its cues are not numbered. This converter handles all three changes and leaves the caption text untouched. The result can be referenced from a track element with kind set to subtitles or captions, or uploaded to platforms that accept .vtt. Files that use the shorter MM:SS,mmm timestamp form are expanded to the full hour-based form that WebVTT expects.
Why does a browser ignore an SRT file in a track element? The track element only accepts WebVTT. It requires the WEBVTT header on the first line and dot-separated milliseconds, so an SRT file is silently ignored and no captions appear. Converting the contents fixes that.
Are cue numbers kept in WebVTT? No. WebVTT cues do not need numbers, so the numbers from the SRT file are dropped. The order and timings of the cues stay exactly the same.
Is the subtitle file uploaded anywhere? No. The conversion happens in the browser on this device, and the download is generated locally.