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SRT to STL Subtitle Converter

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

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SRT
1
00:00:01,000 --> 00:00:04,000
Hello, world!
 
2
00:00:04,500 --> 00:00:08,000
This is a subtitle file.
 
3
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!

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Supports .srt files up to 50 MB

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How It Works

1

Upload SRT File

Drag & drop or select your .srt 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.

About SRT to STL

This converter transforms SubRip (SRT) subtitles into Spruce STL, a plain-text subtitle format used by DVD and legacy authoring tools. The output contains frame-based start and end timecodes, followed by cue text. Multi-line cues are represented with pipe separators.

Input Format

SRT

SRT (SubRip) is a plain-text subtitle format using sequential numbered entries with HH:MM:SS,mmm timestamps. Each cue contains a start time, an end time, and one or more lines of dialogue.

Output Format

STL

Spruce STL is a text-based subtitle format with lines containing a start timecode, end timecode, and subtitle text. This converter writes SMPTE-style HH:MM:SS:FF values at 29.97 fps and separates multiple cue lines with the pipe character.

Features

Converts SRT millisecond timestamps to frame-based STL timecodes
Writes each cue as start time, end time, and subtitle text
Represents multi-line cues with Spruce pipe separators
Keeps conversion local to your browser with no uploads
Free with no sign-up, no watermarks, and files up to 50 MB each

Why Convert?

Some DVD and legacy authoring workflows request Spruce STL rather than plain SRT.
STL stores start and end timecodes in a compact line-oriented layout.
Spruce STL remains useful for exchanging subtitles with older subtitle tools.
The text-based format is easy to inspect before import.

Format Differences

SRT uses numbered cues and HH:MM:SS,mmm timestamps; Spruce STL uses one line per cue with HH:MM:SS:FF timecodes.
SRT keeps cue line breaks; this STL output represents them as pipe separators.
SRT is widely interchangeable; Spruce STL is primarily associated with DVD and legacy authoring tools.
Neither plain SRT nor this Spruce STL output contains a structured styling or metadata section.

Common Use Cases

DVD Authoring

Prepare subtitle text for DVD authoring tools that accept Spruce STL as an import or intermediate format.

Legacy Tool Interchange

Move SRT content into an older subtitle workstation that expects Spruce STL timing and pipe-separated lines.

Pre-Delivery Review

Use the readable line-based output to inspect cue timing and text before importing into an authoring system.

Multi-Format Distribution

Keep SRT for modern platforms and create Spruce STL for a legacy or DVD-specific workflow.

Related Formats

Frequently Asked Questions

It creates Spruce STL, a plain-text subtitle format. It does not create EBU Tech 3264 binary STL. Each cue is written as a start timecode, end timecode, and pipe-separated text.

The converter uses 29.97 fps when writing STL timecodes. If your destination workflow requires a different frame rate, verify whether the resulting timecodes are acceptable before delivery.

No style conversion is performed. The output is plain cue text and timing. HTML-like tags or formatting intended for another player may remain as literal text unless your conversion options remove them.

SRT HH:MM:SS,mmm timestamps are converted to HH:MM:SS:FF timecodes using 29.97 fps. Frame numbers are rounded from milliseconds, so timing is quantized to the nearest output frame.

Line breaks inside an SRT cue are written as pipe separators in STL. Subtitle tools that support Spruce STL can interpret the pipes as separate caption rows.

No. This converter writes Spruce STL text, not EBU Tech 3264 binary STL with GSI and TTI blocks. Do not use the output as an unverified EBU broadcast deliverable.

Ready to convert your subtitles?

Drop your SRT file here and convert to STL instantly.