twineconvert

free · in-browser · no upload

VTT to SBV
Converter

Drop your WebVTT file. We'll convert it to SBV right here in your browser, your file never leaves your device.

or drop your file

Select your file here to get started

or drop your file here.

Accepts .vtt

nothing uploaded no file size cap no signup

How it works

Three steps. No upload, no signup.

  1. 1

    Drop your file

    Click the dropzone above or drag a WebVTT from your desktop. Files of any size, there's no upload, so there's no upload limit.

  2. 2

    Convert in your browser

    The conversion runs entirely in this tab using JavaScript and WebAssembly. Your file never touches our servers, we don't have any.

  3. 3

    Download

    Get your SBV the moment the conversion finishes. Convert another, or close the tab.

Files stay on your device

Your file is never uploaded. The entire conversion runs in your browser using WebAssembly. We can't see what you convert because we have no server to see it.

No file size limit

Server converters cap free users at 1-2 GB and gate larger files behind a paid plan. Since nothing uploads, our limit is whatever your browser can handle.

Free, no signup, no ads on conversions

No account required. No watermark on the output. No queue. Drop a file, get a converted file.

Why convert VTT → SBV

What this conversion is actually for

Both VTT and SBV are subtitle formats; this re-times the cues from one into the other through a shared cue model, so the text and timing carry across exactly. Useful when a player, editor, or platform only accepts SBV. Runs in your browser, nothing is uploaded.

A real example

You have VTT captions but your tool needs SBV. Drop the VTT here and get a SBV file with the same lines and timing.

Troubleshooting

Styling or positioning is lost.

Plain timing and text always carry across. SBV and the plain formats do not carry ASS styling (fonts, colors, positioning), so only the text and timing convert.

Formats involved

About WebVTT and SBV

WebVTT, Web Video Text Tracks

WebVTT is the W3C standard subtitle format for HTML5 video, used by every browser when you set `<track src="captions.vtt">` on a `<video>` element. Differs from SRT mainly in syntax (`.` decimal in timestamps, `WEBVTT` header, no cue numbers required) plus optional cue settings for position and style. YouTube, Vimeo, and modern OTT platforms all accept WebVTT.

How to open

Any text editor. Browsers render WebVTT inline when attached to a video element. Subtitle Edit and other tools convert between WebVTT and SRT.

Full WebVTT format guide →
SBV, SubViewer (YouTube subtitle format)

SBV is YouTube's legacy subtitle download format — `H:MM:SS.mmm,H:MM:SS.mmm` start/end timestamps separated by a comma, then caption text on the next lines. YouTube Studio still exports captions as SBV when you click 'Download captions' in the video editor. Single-digit hours, period decimal, no header.

How to open

Any text editor. Most subtitle editors (Subtitle Edit, Aegisub) auto-detect SBV from the timestamp shape. Convert to SRT/WebVTT for use outside YouTube.

Full SBV format guide →

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FAQ

Common questions

Is this VTT → SBV converter really free?

Yes. No signup, no watermark, no daily file count limit. Every conversion runs in your browser, your file never touches our servers because there are no servers.

Where does my file go when I convert it?

Nowhere. The conversion runs entirely in your browser using JavaScript and WebAssembly. Your file is never uploaded to our servers. We don't have any servers handling files, there's nothing for us to log, store, or accidentally leak.

What's the maximum file size?

Whatever your browser can hold in memory. Practically, this means a few hundred MB on most computers, significantly larger than the 1-2 GB caps that server-upload converters charge for. Very large files (multi-GB) may require closing other browser tabs first.

Why convert WebVTT to SBV?

HTML5 video captions and accessibility tracks. Downloading and editing YouTube auto-generated captions. The most common reason to convert is compatibility, SBV works in places where WebVTT doesn't, or vice versa.

How do I open a WebVTT file in the first place?

Any text editor. Browsers render WebVTT inline when attached to a video element. Subtitle Edit and other tools convert between WebVTT and SRT.

Does this work offline?

Once the page is loaded, the conversion itself runs entirely offline. The first time you use a tool, your browser downloads the conversion library (a one-time cache). If you reload while offline, the page won't load, but you can install the site as a Progressive Web App for full offline use.

Can I convert multiple files at once?

Single file at a time for now. Batch conversion is on the roadmap, for now, drop one file, download the result, then convert the next.