Free EBU STL to VTT Converter: No Sign-up, Files Never Uploaded
This free EBU STL to VTT converter runs entirely on your device. You do not need an account or a login, and your files are never uploaded, so they never leave your browser.
Every cue is read with its start and end time, then written again in the VTT layout.
This pair runs on code that is already in the page, so there is no extra engine to download.
- Free
- No sign-up
- Never uploaded
- No watermark
Your files are converted on your device and never uploaded.
How to convert
- Add your EBU STL files by dragging them onto the converter or by using the file picker.
- Check that VTT is the selected target format; it is already chosen on this page.
- Open the options if you want to change frame rate and text encoding, or keep the defaults.
- Press Convert and watch the progress shown for each file.
- Download each result, or take them all together as one ZIP when you converted several files.
Features
- Reads .stl and writes .vtt.
- Free, with no watermark added to the result.
- No sign-up and no login.
- Your files are never uploaded and never leave your device.
- Batch conversion with a ZIP download for several results.
- The input is recognised by its content, not only by its file name.
Supported formats
| Format | Read | Write | Notes |
|---|---|---|---|
| EBU STL.stl | Yes | No | EBU STL is a broadcast format that is read only here; convert it to SRT or VTT. |
| WebVTT (VTT).vtt | Yes | Yes | The W3C subtitle format used by the HTML video element. |
About the formats
About EBU STL
Binary subtitle format defined by the European Broadcasting Union for TV.
Not related to the 3D STL format that shares the extension.
About VTT
The W3C subtitle format used by the HTML video element.
Supports basic styling and positioning.
EBU STL vs VTT
EBU STL does not support transparency, and VTT does not.
EBU STL files use the .stl extension and WebVTT (VTT) files use .vtt, so the converted file gets a new name with the new extension.
Privacy: how it works
- Your EBU STL files stay on your device. The page reads each file with the browser's file API, converts it with code running in the tab, and hands the result back as a download. No upload happens, so there is no copy of your file on our servers to protect, delete or leak.
- There is nothing to sign up for and no login. The converter does not ask for an email address, and it does not need to know who you are to do its job.
- You can check the claim yourself: open your browser developer tools, watch the Network tab while a file converts, and you will see no request that carries your file.
Tips
- Open the result in your player to check that the timing still lines up.
- Use UTF-8 for text encoding unless an older device needs something else.
- Styling, colours and positions only survive between formats that support them.
- Keep the original file in case you need the styling later.
- This page converts one way only; VTT files cannot be turned back into EBU STL here.
Frequently asked questions
Is it really free?
Yes. There is no price, no trial, no credit card and no watermark added to your results. Ulkaa Tool does the conversion with your own device, so there is no server bill to pass on to you.
Are my files uploaded?
No. Your EBU STL files are read and converted inside your browser and are never sent to Ulkaa or to anyone else. The result is created on your device and you save it from there.
Do I need an account?
No. There is no sign-up and no login. Open the page, add your files and convert. An Ulkaa account is not needed for anything on this tool.
Is there a file size limit?
No limit is set by us. The real limit is your device: the conversion uses your own memory and processor, so very large files can be slow, and a very big batch may need to be split into smaller runs.
What is the difference between EBU STL and VTT?
EBU STL does not support transparency, and VTT does not. EBU STL files use the .stl extension and WebVTT (VTT) files use .vtt, so the converted file gets a new name with the new extension.
Can I convert many EBU STL files at once?
Yes. Add as many files as your device can handle. Each one is converted on its own and you can download them one by one or as a single ZIP.
Will anything be lost when I convert EBU STL to VTT?
The converter keeps the content of the file. Check the result once, since small differences in metadata or colour handling can happen between formats.
Can I convert VTT back to EBU STL?
Not on this page. This conversion goes one way. Open the VTT page to see which formats it can be converted to.
Related conversions
- EBU STLSubRip (SRT)Subtitle
- SubRip (SRT)WebVTT (VTT)Subtitle
- Advanced SubStation Alpha (ASS)WebVTT (VTT)Subtitle
- SubStation Alpha (SSA)WebVTT (VTT)Subtitle
- YouTube captions (SBV)WebVTT (VTT)Subtitle
- MicroDVD (SUB)WebVTT (VTT)Subtitle
- Lyrics (LRC)WebVTT (VTT)Subtitle
- TTML / DFXPWebVTT (VTT)Subtitle
- SAMI (SMI)WebVTT (VTT)Subtitle
- WebVTT (VTT)SubRip (SRT)Subtitle
- WebVTT (VTT)Advanced SubStation Alpha (ASS)Subtitle
- WebVTT (VTT)Plain text (TXT)Subtitle