SSA to SMI 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
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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 SMI Converter
Our SSA to SMI converter reads SubStation Alpha input and produces a single-language Synchronized Accessible Media Interchange document entirely in your browser. Source SSA timing (H:MM:SS.cc centiseconds) is converted to SMI millisecond Start attributes. SSA override tags are stripped, HTML special characters are escaped, line breaks become <br> tags, and a blank SYNC element marks each cue end. 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
SMISMI (SAMI, Synchronized Accessible Media Interchange) is a Microsoft subtitle format using HTML-like <SYNC> elements with Start times in milliseconds. SMI supports multiple language tracks through CSS classes and is suitable for Windows Media Player and legacy accessibility workflows.
Features
Why Convert?
Format Differences
Common Use Cases
Windows Media Captions
Produce SMI captions for Windows Media Player and Microsoft-based playback environments.
Accessibility
Deliver SAMI accessibility captions for legacy corporate and educational media systems.
Multi-Language Files
Create a single-language SMI track that you can extend in SAMI-aware tooling if multiple classes are required.
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.
TTML (Timed Text Markup Language)
The structured XML alternative: convert to TTML when a basic timed-text document is more suitable.
Frequently Asked Questions
It reads a SubStation Alpha file, parses each cue's timing and text, and writes a single-language SAMI document with an ENCC class, timed SYNC elements, escaped HTML text, and blank end markers. Source SSA timing is converted to SMI millisecond Start attributes.
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 <br> tags, and HTML special characters are escaped. Timing is converted to SMI milliseconds.
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 SMI timing (whole milliseconds (Start=...)).
Yes. The responsive page works in modern mobile browsers.