Turn SRT subtitle files into WebVTT captions that web players and the HTML5 track element can load, right in your browser. Nothing is uploaded, and there’s no account, watermark or limit.
Drop your .srt files on the area that says “Drop SRT files here”, or use “or tap to choose files”. You can add a whole season or every lesson of a course at once.
Each file is converted the moment it lands: its row shows the new .vtt name, the number of lines and an encoding note such as “Already UTF-8” or “Windows-1256 → UTF-8”.
Click “Preview” to compare the first 100 cues in the “#”, “Before”, “After” and “Text” columns and see the commas turned into dots.
Save each WebVTT file with “Download”, or grab the whole batch with “Download all (.zip)”. Use “Clear list” to start over.
WebVTT (Web Video Text Tracks, file extension .vtt) is the caption format of the web. The HTML5 track element, which attaches subtitles to a video tag, only accepts WebVTT in browsers, so a site, a custom player or a learning platform built on standard HTML5 video needs a .vtt file even when your translator delivered an .srt.
The format grew out of SRT, so the two look almost the same. A WebVTT file must start with the word WEBVTT on its first line, and its times use a dot before the milliseconds (00:01:02.345) where SRT uses a comma (00:01:02,345). The number above each SRT block becomes an optional cue identifier.
WebVTT goes further than SRT. Cue settings after the time line control placement (line, position, align, size). A STYLE block or the page's CSS can style captions through the ::cue selector, and the format adds NOTE comments, regions, speaker voices and classes. SRT has none of that officially; players simply tolerate font tags and {\an8}-style codes borrowed from other formats.
filetidy keeps italic, bold and underline tags, which WebVTT supports. Font colour and face tags are dropped because WebVTT has no font tag. Position codes {\an1} to {\an9} become real cue settings, so a line marked {\an8} still shows at the top of the frame. Other {\…} codes are removed, and & or stray angle brackets in the text are escaped as the format requires.
YouTube
YouTube reads both SRT and WebVTT, so you don't need to convert just for YouTube. Converting helps when the same captions must also play on your own site.
VLC
VLC is a quick local test. Browsers apply their own caption styling, so text size and background can look different once the file plays on a web page.
Pick WebVTT whenever the video plays in a browser: your own site, a player you embed, an online course. It is the only caption format the HTML5 track element reads, and it lets you place and style captions with CSS.
Keep SRT for desktop players, TVs, USB sticks and video editors. Many of those read WebVTT poorly or not at all, while SRT works almost everywhere. When a platform accepts both, as YouTube does, either is fine.
Converting is lossless for the text and timing: only the header, the time separator and the tags change. Keep the original .srt as your master copy and generate the .vtt from it when you publish, so later fixes only need to be made once.
Both are plain-text caption files with numbered or labelled cues and start and end times. WebVTT adds a WEBVTT header, uses a dot instead of a comma in times, and supports positioning, CSS styling, comments and regions. SRT is simpler and better supported by TVs and offline players.
Usually not. Without the WEBVTT header browsers reject the file, and many reject commas in the timestamps too. Renaming also leaves font tags and position codes that WebVTT doesn't understand. The converter fixes all of this and saves the result as UTF-8.
Check that the track element points to the right path and has kind, srclang and label set, and add the default attribute if captions should be on from the start. If the .vtt is on another domain, the server must allow cross-origin requests and the video needs the crossorigin attribute. Some servers also send .vtt with the wrong MIME type; it should be text/vtt.
Italic, bold and underline survive unchanged. Lines tagged {\an8} stay at the top of the picture, and the other {\an} codes are turned into matching line, position and align settings. Colour and font tags are removed, since WebVTT handles colours through CSS instead.
Yes, in most cases. The original encoding is detected automatically, including Windows-1256 for Arabic and Windows-1252 for French, and the WebVTT file is always written in UTF-8, the only encoding the format allows. The file row tells you which conversion was applied.
No. The conversion runs in JavaScript inside your browser tab, so scripts, unreleased translations and course material stay on your computer. There is no account, no limit on the number of files and no fee.
Normally no, which is why the “Add a BOM (UTF-8 with signature)” option is off by default. Browsers and web players read UTF-8 WebVTT without it. Tick it only if a specific tool you use insists on a BOM.
Last updated October 28, 2026
Some TVs and older Windows players need it to show accents and Arabic. The web doesn’t.