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VTT to STL Subtitle Converter

Fast. Private. Perfect.

100% local processing in your browser. No upload. No waiting.

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VTT
WEBVTT
 
00:00:01.000 --> 00:00:04.000
Hello, world!
 
00:00:04.500 --> 00:00:08.000
This is a subtitle file.
 
00:00:08.500 --> 00:00:12.000
Converted locally!
STL
// Spruce Subtitle File
// Format: Start Time, End Time, Subtitle Text
 
00:00:01:00 , 00:00:04:00 , Hello, world!
00:00:04:15 , 00:00:08:00 , This is a subtitle file.
00:00:08:15 , 00:00:12:00 , Converted locally!

Drag & drop your VTT file here

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Supports .vtt files up to 50 MB

100% LocalNo UploadSecureInstant

How It Works

1

Upload VTT File

Drag & drop or select your .vtt file

2

Convert Instantly

We process it locally in your browser

3

Download STL

Get your .stl file immediately

Why Choose AllSubConverter?

Your Privacy Matters

Everything runs in your browser. Your files are never uploaded.

Lightning Fast

Optimized processing engine converts files in seconds.

Free & Local

Each file can be up to 50 MB. Batches can contain up to 200 files or 1 GB total.

Works Everywhere

Works on Windows, Mac, Linux, iOS, Android - any modern browser.

Free Online VTT to STL Converter

This browser-based converter reads timestamped WebVTT cue blocks and writes a text-based Spruce STL file. Each cue becomes one start-time, end-time, and text entry. Timing is quantized to a 29.97 fps frame grid, cue line breaks become vertical bars, and VTT cue identifiers and settings are discarded.

Input Format

VTT

VTT (WebVTT) is a text subtitle format for web video. A VTT file starts with a WEBVTT header and uses HH:MM:SS.mmm --> HH:MM:SS.mmm cue timing. It can also contain cue identifiers, cue settings, inline tags, NOTE blocks, and style metadata.

Output Format

STL

The output is Spruce STL, a plain-text subtitle format with cue entries written as start time, end time, and text. It is not EBU Tech 3264 binary STL and does not contain EBU GSI or TTI structures.

Features

Reads timestamped WebVTT cue blocks directly in your browser
Writes text-based Spruce STL cue entries
Converts timing to HH:MM:SS:FF values on a 29.97 fps frame grid
Converts cue line breaks to vertical bars
Discards VTT cue identifiers and cue settings
Processes files up to 50 MB without uploading them

Why Convert?

Some DVD and legacy subtitling workflows accept Spruce STL text files.
STL cue entries separate start time, end time, and text in a compact line.
Vertical-bar line separators are common in text-based authoring workflows.
A frame-grid timing version can be easier to compare with video timing.
Converting locally avoids uploading program material or caption text.
Keeping VTT and STL copies supports different playback environments.

Format Differences

VTT uses a WEBVTT header and cue blocks; Spruce STL uses plain-text cue entries.
VTT timing uses milliseconds; this STL output uses HH:MM:SS:FF frame values.
VTT supports cue settings and positioning; those settings are discarded.
VTT line breaks become vertical bars in the STL text field.
VTT inline tags remain literal text rather than becoming STL styling.
VTT comments and identifiers are not carried over.

Common Use Cases

Basic STL Draft

Create a text-based Spruce STL draft from web subtitles before checking it in the target authoring tool.

Legacy Tool Interchange

Move timestamped VTT cues into a workflow that requests Spruce STL input.

Text Review

Produce a plain-text file with cue timing and text on one line for quick inspection.

Local Conversion

Convert subtitles without uploading them to a separate conversion service.

Web and STL Copies

Keep a VTT version for web playback while producing a basic STL copy for another workflow.

Frame-Grid Timing Review

Review millisecond VTT timing after quantization to a 29.97 fps frame grid.

Related Formats

VTT (WebVTT)

The readable web-video input format used by this converter.

SRT (SubRip)

A widely supported timestamped subtitle format for media players.

SCC (Scenarist Closed Captioning)

A CEA-608 caption format used in some North American caption workflows.

Frequently Asked Questions

No. The output is text-based Spruce STL. It does not create the binary EBU Tech 3264 format or EBU GSI and TTI structures.

Cue identifiers and settings such as line, position, size, and align are discarded. The STL output contains timing and text only.

No. NOTE blocks do not contain displayable cue text for this converter and are ignored.

Each cue start and end is converted to HH:MM:SS:FF values on a 29.97 fps frame grid. This converter does not expose a frame-rate selector.

Physical cue line breaks are converted to vertical bars in the STL text field. VTT inline tags remain as literal source text.

No. VTT styling, cue settings, and CSS blocks are not mapped to STL styling. Tags present inside cue text remain literal text.

Ready to convert your subtitles?

Drop your VTT file here and convert to STL instantly.