SSA to STL Subtitle Converter
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100% local processing in your browser. No upload. No waiting.
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Supports .ssa files up to 50 MB
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How It Works
Upload SSA File
Drag & drop or select your .ssa file
Convert Instantly
We process it locally in your browser
Download STL
Get your .stl file immediately
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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 SSA to STL Converter
Our SSA to STL converter reads SubStation Alpha input and produces Spruce Subtitle text output entirely in your browser. Source SSA timing is converted to SMPTE-style HH:MM:SS:FF timecodes at 29.97 fps. SSA override tags are stripped, and cue line breaks become pipe characters. The conversion runs client-side, so your subtitle files are never uploaded to a server.
Input Format
SSASSA (SubStation Alpha v4) is the predecessor to ASS and shares the same section-based structure: [Script Info], [V4 Styles], and [Events] with Dialogue lines. SSA supports fonts, colors, and basic positioning but predates some ASS additions such as blur. Because SSA and ASS use the same Dialogue layout, they are parsed identically.
Output Format
STLSTL (Spruce Subtitle) is a text-based subtitle format used in DVD authoring and some broadcast workflows. Entries use comma-separated start and end timecodes followed by subtitle text, with the pipe character (|) for line breaks. The output is accepted by DVD authoring tools and Spruce-based workflows.
Features
Why Convert?
Format Differences
Common Use Cases
DVD Authoring
Produce STL subtitle files for DVD authoring tools that expect the Spruce format.
Broadcast Workflows
Generate Spruce STL text for tools that expect this subtitle layout.
Frame-Accurate Timing
Output frame-based timecodes quantized to the generator's 29.97 fps grid.
Related Formats
SRT (SubRip)
The universal plain-text alternative: convert to SRT for maximum device compatibility.
VTT (WebVTT)
The web alternative: convert to VTT if your target is HTML5 video or YouTube.
SCC (Scenarist Closed Captioning)
The North American broadcast alternative: convert to SCC for CEA-608 caption delivery.
Frequently Asked Questions
It reads a SubStation Alpha file, parses each cue's timing and text, and writes a Spruce STL text file with the standard header, comma-separated timecodes, and pipe-separated cue lines. Source SSA timing is converted to SMPTE-style HH:MM:SS:FF values at 29.97 fps.
Absolutely. Every conversion runs client-side in your browser. No subtitle data, file contents, or metadata is ever transmitted to a server.
Yes. SSA styling and override tags are dropped, line breaks become pipe characters, and timing is quantized to the output frame grid.
Yes, completely free with no sign-up, no watermarks, and files up to 50 MB each. All processing happens in your browser, so your files are never uploaded to a server.
Source SSA timing (H:MM:SS.cc centiseconds) is converted to STL timing (SMPTE HH:MM:SS:FF frame timecodes).
Yes. The responsive page works in modern mobile browsers.