SMI to SCC Converter
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100% local processing in your browser. No upload. No waiting. No limits.
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Supports .smi 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 SMI to SCC Converter
Our SMI to SCC converter reads Synchronized Accessible Media Interchange input and produces Scenarist Closed Captioning output entirely in your browser. Source SMI timing (whole milliseconds (Start=...)) is converted to SCC timing (SMPTE HH:MM:SS:FF at 29.97fps). 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
SMISMI (SAMI, Synchronized Accessible Media Interchange) is a Microsoft subtitle format built from HTML-like <SYNC> elements whose Start attribute is given in milliseconds. SMI supports multiple language tracks through CSS classes and was widely used for Windows Media Player captions and accessibility content.
Output Format
SCCSCC (Scenarist Closed Captioning) is the industry-standard format for delivering CEA-608 (Line 21) closed captions to North American broadcast television and streaming services. SCC encodes caption text as hexadecimal byte pairs paired with SMPTE timecodes at 29.97 fps and begins with a Scenarist_SCC V1.0 header.
Features
Why Convert?
Format Differences
Common Use Cases
Broadcast Caption Delivery
Produce SCC files for delivery to television networks, cable operators, and playout systems requiring CEA-608.
Streaming Compliance
Generate SCC to meet Netflix, Amazon Prime, or Hulu caption delivery specifications.
FCC Compliance
Deliver CEA-608 compliant SCC files to satisfy FCC closed-captioning requirements.
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.
STL (Spruce Subtitle)
The DVD/broadcast alternative: convert to STL for Spruce or DVD authoring workflows.
Frequently Asked Questions
It reads a Synchronized Accessible Media Interchange file, parses each cue's timing and text, normalizes the structure for Scenarist Closed Captioning, and writes a valid .scc file. Source SMI timing (whole milliseconds (Start=...)) is converted to SCC timing (SMPTE HH:MM:SS:FF at 29.97fps).
Absolutely. Every conversion runs client-side in your browser. No subtitle data, file contents, or metadata is ever transmitted to a server.
SMI and SCC 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 SMI timing (whole milliseconds (Start=...)) is converted to SCC timing (SMPTE HH:MM:SS:FF at 29.97fps).
Yes. The converter is fully responsive and works in any modern mobile browser on iOS and Android.