ASS to SMI Converter
Fast. Private. Perfect.
100% local processing in your browser. No upload. No waiting. No limits.
Drag & drop your ASS file here
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Supports .ass files up to any size
More Subtitle Tools
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.
Truly Unlimited
No file size limits. No daily limits. Completely free.
Works Everywhere
Works on Windows, Mac, Linux, iOS, Android - any modern browser.
Free Online ASS to SMI Converter
Our ASS to SMI converter reads Advanced SubStation Alpha input and produces Synchronized Accessible Media Interchange output entirely in your browser. Source ASS timing (H:MM:SS.cc centiseconds) is converted to SMI timing (whole milliseconds (Start=...)). Styling and markup that the target format cannot represent are normalized or stripped, leaving valid, ready-to-use output. The conversion runs client-side, so your subtitle files are never uploaded to a server.
Input Format
ASSASS (Advanced SubStation Alpha v4+) is an extended subtitle format used heavily in anime distribution. It features a [Script Info] header, a [V4+ Styles] section defining fonts, colors, outlines, and shadows, and an [Events] section of Dialogue lines carrying inline override tags such as {\pos}, {\blur}, and {\fad}. Timing uses centisecond precision (H:MM:SS.cc). ASS supports positioning, vector drawing, and karaoke effects.
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
Use SMI's CSS classes to carry multiple language tracks in a single caption file.
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 streaming alternative: convert to TTML for Netflix, Apple TV, or broadcast delivery.
Frequently Asked Questions
It reads an Advanced SubStation Alpha file, parses each cue's timing and text, normalizes the structure for Synchronized Accessible Media Interchange, and writes a valid .smi file. Source ASS timing (H:MM:SS.cc centiseconds) is converted to SMI timing (whole milliseconds (Start=...)).
Absolutely. Every conversion runs client-side in your browser. No subtitle data, file contents, or metadata is ever transmitted to a server.
ASS and SMI both support styling, but their styling models differ. Styling that cannot be mapped is normalized or dropped, while dialogue text and timing are always preserved.
Yes, completely free with no sign-up, no watermarks, and no file size limits. All processing happens in your browser, so your files are never uploaded to a server.
Source ASS timing (H:MM:SS.cc centiseconds) is converted to SMI timing (whole milliseconds (Start=...)).
Yes. The converter is fully responsive and works in any modern mobile browser on iOS and Android.