What frame rate does STL use?

EBU STL is standardized at 25fps (the European PAL broadcast frame rate). The converter uses 25fps for frame-to-millisecond conversion.

Does it work on mobile?

Yes. The converter is fully responsive and works in mobile browsers on iOS and Android.

Is my data sent to a server?

No. All parsing happens locally in your browser. Your STL files never leave your device.

How fast is the conversion?

Nearly instant for typical subtitle files. Large STL files with thousands of entries process in under a second.

What encoding does the output use?

UTF-8, which supports all languages including accented European characters, CJK, Arabic, and Cyrillic.

Can I edit the SRT after conversion?

Yes. The output is a standard plain-text SRT file that opens in any text editor for modifications.

What are STL vertical position codes?

STL entries include a vertical position code for screen placement. SRT does not support positioning, so this information is not carried over.

Does the converter handle binary STL files?

STL can be stored as text or binary. The converter handles the text-based STL format.

Where do STL files come from?

STL files are produced by European subtitle creation software, used in DVD authoring workflows, and exchanged between EBU broadcasters.

Can I batch convert STL files?

Yes. Process each file in turn within the converter. Each produces a separate .srt output.

What is the difference between STL and SCC?

STL is the European broadcast standard (25fps, structured data blocks), while SCC is the North American broadcast standard (29.97fps, hex-encoded CEA-608 captions).

Does it preserve STL justification codes?

STL entries include justification codes for alignment. SRT has no justification metadata, so this information is lost.

Can I use the SRT output for streaming?

Yes. SRT is accepted by most streaming platforms. For web streaming, convert STL to VTT instead.

STL to SRT Converter

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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!

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!

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Supports .stl files up to any size

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How It Works

Upload STL File

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Get your .srt file immediately

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Free Online STL to SRT Converter

Our STL to SRT converter reads EBU STL (Subtitle Transmission List) files used in European broadcast and DVD production, and converts them into universally compatible SubRip format. STL files contain structured subtitle data with GSI header metadata and TDI text entries, using frame-based timing at 25fps (EBU standard). This tool parses the STL structure, extracts the subtitle text, converts the frame-based timecodes to SRT millisecond timestamps, and produces a standard .srt file that works on any device worldwide.

Input Format

STL

STL (EBU STL, Subtitle Transmission List) is a subtitle format standardized by the European Broadcasting Union (EBU Tech 3264) for television subtitling and DVD production. STL files contain a header block (GSI - General Subtitle Information) with metadata like program title, translator, revision, and frame rate, followed by subtitle data entries (TDI - Text Data Information) containing timing, text, and extension data. STL is the standard format for European broadcast workflows, DVD authoring, and DVB subtitling in EBU member countries.

Output Format

SRT

SRT (SubRip) is the most universally supported subtitle format. Each entry has a sequential index number, a timestamp line in HH:MM:SS,mmm --> HH:MM:SS,mmm format (comma before milliseconds, arrow separating start and end), and subtitle text. SRT files are plain text and recognized by virtually every media player, smart TV, video editor, and streaming platform.

Features

Parses EBU STL structure including GSI header and TDI subtitle data blocks

Extracts subtitle text from STL text fields with proper character handling

Converts 25fps frame-based timecodes to SRT millisecond timestamps

Handles STL vertical position and justification codes

Preserves text content including accented European characters

Outputs clean SRT with sequential numbering and standard timestamp format

Why Convert?

STL is used primarily in European broadcasting; SRT is universal and works on all devices globally.

Smart TVs, mobile players, and desktop media players do not support STL but all support SRT.

Video editing software like Premiere Pro and DaVinci Resolve import SRT natively but may not read STL.

STL is a structured format with fixed-width fields; SRT is simple plain text that is easy to inspect and edit.

Media servers like Plex and Emby auto-detect SRT but do not recognize STL files.

STL uses 25fps EBU timing; SRT uses millisecond timing that works at any frame rate.

Convert European broadcast subtitles for use in international video distribution and streaming.

Format Differences

STL uses a structured format with GSI header and TDI data blocks; SRT is a simple sequential text list.

STL uses frame-based timecodes (HH:MM:SS:FF at 25fps); SRT uses millisecond timestamps (HH:MM:SS,mmm).

STL stores metadata (title, translator, language) in the GSI header; SRT has no metadata section.

STL text fields use fixed-width character encoding with EBU character sets; SRT uses variable-width UTF-8.

STL supports vertical position and justification codes per entry; SRT has no positioning metadata.

STL is primarily for European broadcast; SRT is accepted worldwide by all players and platforms.

Common Use Cases

European Broadcast Conversion

Convert EBU STL subtitles from European television productions into SRT for international distribution across global streaming platforms.

DVD Subtitle Extraction

Extract subtitle text from DVD production STL files and convert to SRT for use in modern digital video workflows.

Post-Production Import

Load European broadcast subtitles into Premiere Pro, DaVinci Resolve, or Final Cut by converting STL to the universally supported SRT.

Media Server Library

Add readable subtitles to your Plex or Jellyfin library by converting STL files to SRT, which these servers auto-detect.

Subtitle Standardization

Normalize a mixed library of STL, SRT, and VTT files into consistent SRT format for easier management and playback.

International Distribution

Prepare European-produced subtitles for worldwide digital distribution by converting from the regional STL format to universal SRT.

Related Formats

STL (EBU STL)

The input format: European broadcast standard with structured data blocks and frame-based timing at 25fps.

VTT (WebVTT)

The web alternative: if your target is HTML5 video or YouTube, convert STL to VTT instead.

SCC (Scenarist Closed Captioning)

The North American broadcast equivalent: used for CEA-608 caption delivery in US television.

Frequently Asked Questions

What is EBU STL?

EBU STL (Subtitle Transmission List, EBU Tech 3264) is a subtitle format standardized by the European Broadcasting Union for television subtitling. It contains a GSI header block with metadata and TDI data blocks with subtitle text and timing.

What is the GSI header?

The GSI (General Subtitle Information) block is the first 1024 bytes of an STL file. It contains metadata including the original program title, episode title, translator name, language code, and frame rate.

Is the STL to SRT converter free?

Yes, completely free with no registration or watermarks. All parsing happens in your browser.

How are STL timecodes converted to SRT timestamps?

STL uses HH:MM:SS:FF timecodes at 25fps (the European broadcast standard). The converter multiplies the frame number by 40ms (1000/25) to produce SRT millisecond timestamps (HH:MM:SS,mmm).

What is a TDI block?

TDI (Text Data Information) blocks follow the GSI header. Each TDI contains a subtitle entry with timing (start and end timecodes), text, vertical position code, and justification code.

Does the converter handle European characters?

Yes. STL uses EBU character sets that include accented European characters. The converter maps these to their UTF-8 equivalents in the SRT output.

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Related Resources

What is STL?What is SRT?