Does it work on mobile?

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

Is my data sent to a server?

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

How fast is the conversion?

Nearly instant. HTML parsing and text extraction are computationally lightweight.

What encoding does the output use?

UTF-8, supporting all languages including Korean, Chinese, Japanese, and other CJK characters.

Does it preserve SAMI styling?

No. SAMI CSS styling (fonts, colors, positioning) is removed because SRT does not support styling. Only the plain text content is preserved.

Can I edit the SRT after conversion?

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

What happens to SAMI HEAD metadata?

SAMI files have an HTML HEAD section with TITLE and STYLE elements. This metadata is not carried over to SRT, which has no metadata section.

Does it handle SAMI files with errors?

Malformed SYNC entries are skipped without an itemized warning. Check the output if the source file is damaged or unusually structured.

Can I batch convert SMI files?

Yes. Drop several SMI files on this page and they open together in the workspace Batch tool with the SRT format pre-selected, converting every file at once. For converting whole folders at scale, use the Batch Converter page.

What is the difference between SAMI and SRT?

SAMI is an HTML-based format with CSS styling and multi-language support, designed for Windows Media Player. SRT is a simple plain-text format with timestamps, supported by virtually every modern player.

Why do Korean platforms use SMI?

SAMI became popular in Korea because it supported Korean text rendering and CSS styling in the Windows Media Player era. Many Korean subtitle archives still distribute content in SMI format.

Does the converter handle SYNC elements without End times?

SAMI SYNC elements only have Start times. The converter calculates the end time from the next SYNC element's Start value. The last entry gets a default duration.

Can I use the SRT for streaming?

Yes. SRT is widely accepted. For web streaming, convert SMI to VTT instead.

SMI to SRT Subtitle Converter

Parse SAMI subtitle files and extract clean text into universally compatible SRT format.

Drag & drop your SMI file here

or click to browse

Supports .smi, .sami, .html files up to 50 MB

Core Engine Architecture

Free Online SMI to SRT Converter

Our SMI to SRT converter parses SAMI (Synchronized Accessible Media Interchange) files, a Microsoft format that wraps subtitle text in HTML-like SYNC elements, and extracts the content into plain SubRip format. SAMI files store timing as millisecond offsets in Start attributes, use CSS classes for styling and language tracks, and contain HTML tags throughout. This tool strips the HTML structure, extracts the subtitle text from each SYNC block, converts millisecond timing to SRT HH:MM:SS,mmm format, and produces a clean .srt file that works on any device.

Payload & Syntax Inspector

SMI to SRT Code Syntax & Structure Inspection

Side-by-side code inspection illustrating header definitions, timestamp syntax, and cue payload formatting

Millisecond Sync

input.smi

SMI SOURCE

<SAMI>
<BODY>
<SYNC Start=1000><P Class=ENCC>Hello, world!</P>
<SYNC Start=4000><P Class=ENCC>&nbsp;</P>
<SYNC Start=4500><P Class=ENCC>This is a subtitle file.</P>
<SYNC Start=8000><P Class=ENCC>&nbsp;</P>
<SYNC Start=8500><P Class=ENCC>Converted locally!</P>
<SYNC Start=12000><P Class=ENCC>&nbsp;</P>
</BODY>
</SAMI>

output.srt

SRT RESULT

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!

Specification Sheet

SMI vs SRT Technical Specifications

Standard Compliant

Input Format

SMI

SMI (SAMI, Synchronized Accessible Media Interchange) is a subtitle format developed by Microsoft for Windows Media Player. SAMI files use an HTML-like structure where each subtitle entry is enclosed in SYNC elements, with a Start attribute giving the display time in milliseconds. The format supports CSS styling, multiple language tracks via CLASS attributes, and metadata in the document head. SAMI is still found on Korean video platforms, older media archives, and educational content.

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.

Format Differences

SAMI uses HTML structure with SYNC elements; SRT uses numbered entries with arrow timestamps.

SAMI stores timing as millisecond offsets (Start=1234); SRT uses HH:MM:SS,mmm --> HH:MM:SS,mmm format.

SAMI supports CSS styling and CLASS-based language tracks; SRT has no styling or language metadata.

SAMI wraps text in P and other HTML tags; SRT stores plain text only.

SAMI requires an HTML parser to read; SRT is simple plain text that any tool can parse.

SAMI files have HEAD and BODY sections like HTML; SRT has no document structure.

Conversion Troubleshooting & Gotchas

Practical solutions for player compatibility, character encoding, and timing synchronization

4 Common Gotchas

GOTCHA #1

Subtitle timing drifts or appears out of sync on media players

Video files frequently differ in framerate (e.g., 23.976 fps vs 25 fps). If the timing drifts steadily, use our Subtitle Sync tool to adjust the global offset or framerate stretch.

GOTCHA #2

Characters appear as garbled symbols or question marks (Mojibake)

Legacy files saved in Windows-1252, Shift-JIS, or GBK may render incorrectly. Our exporter standardizes output to clean UTF-8. Use our Subtitle Encoding Converter if the source file is corrupted.

GOTCHA #3

Overlapping captions when multiple speakers talk simultaneously

Different formats handle overlapping dialogue differently. If your target player cannot render stacked cues cleanly, open the file in our Subtitle Editor to adjust individual cue timings.

GOTCHA #4

Video editing software (Premiere, DaVinci, Final Cut) rejects the file

Professional NLE software enforces strict syntax rules. Our converter eliminates malformed line breaks and non-standard tags, producing clean, standardized files.

Features

Parses SAMI HTML structure including SYNC elements and P tags

Extracts subtitle text from HTML content, stripping all markup

Converts millisecond timing offsets to SRT HH:MM:SS,mmm timestamps

Reads SYNC blocks without requiring a selected language class

Strips HTML tags, entities, and styling from subtitle text

Outputs clean SRT with sequential numbering and standard format

Why Convert?

SAMI is a legacy Microsoft format that few modern players support; SRT is universal.

Smart TVs, mobile devices, and modern media players cannot read SMI files.

Video editing tools import SRT natively but do not recognize SAMI format.

Korean video platforms often distribute subtitles as SMI, which needs conversion for international use.

SAMI files contain HTML markup that clutters the text; SRT is clean plain text.

SAMI stores timing as raw milliseconds; SRT uses the standard HH:MM:SS,mmm format that humans can read.

Media servers like Plex and Emby auto-detect SRT but ignore SMI files.

Scenarios

Common Use Cases

Korean Platform Migration

Convert SMI subtitles from Korean video platforms (Naver TV, KakaoTV) into SRT for use on international streaming services and players.

Legacy Archive Conversion

Transform old SAMI subtitle files from Windows Media Player era archives into modern SRT format for current video workflows.

Educational Content

Convert SAMI subtitles from educational CD-ROMs or older e-learning content into SRT for modern video platforms.

Media Server Library

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

Plain-Text Cleanup

Remove SAMI HTML structure and styling while retaining readable timed text for everyday players.

Subtitle Standardization

Normalize a mixed collection of SMI, SRT, and VTT files into consistent SRT format for easier management.

Format Ecosystem

Related Formats

SMI (SAMI)

The input format: HTML-like Microsoft subtitle format with SYNC elements and CSS styling.

VTT (WebVTT)

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

SCC (Scenarist Closed Captioning)

The broadcast alternative: if you need broadcast caption delivery, convert SMI to SCC.

How It Works

1
Upload your .smi file by dragging it into the converter or browsing.
2
The parser reads the HTML structure and identifies each SYNC element.
3
Subtitle text is extracted from within P tags, with HTML markup stripped.
4
Millisecond Start values are converted to SRT HH:MM:SS,mmm timestamp format.
5
End times are calculated from the next SYNC element's Start value.

moreTools.fromFormat

SMI VTT SMI ASS SMI LRC SMI TXT SMI TTML SMI SCC SMI STL

moreTools.toFormat

VTT SRT ASS SRT LRC SRT JSON SRT SBV SRT SSA SRT TTML SRT SCC SRT

More Subtitle Tools

Subtitle Format Cleaner

Remove formatting, tags and noise

Subtitle Editor

Edit subtitle content and timings

Subtitle Sync & Timing Calibration

Adjust timing with millisecond precision

Subtitle Merger

Combine multiple subtitle files

AI Subtitle Translator

Translate to 19 built-in target languages

Frequently Asked Questions

SAMI (Synchronized Accessible Media Interchange) is a subtitle format developed by Microsoft. It uses HTML-like syntax with SYNC elements for timing, CSS for styling, and supports multiple language tracks via CLASS attributes. It was designed for Windows Media Player.

Yes. SAMI wraps subtitle text in HTML tags like P, BR, FONT, and B. The converter strips all HTML markup and extracts only the visible text content for the SRT output.

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

SAMI stores display time as a millisecond offset in the Start attribute of SYNC elements (e.g., Start=1234 means 1.234 seconds). The converter transforms this into SRT HH:MM:SS,mmm format. End times are derived from the next SYNC element's Start value.

The converter does not provide language-track selection. It extracts the visible text found in each SYNC segment, so files that carry multiple CLASS-based languages should be reviewed for duplicate or mixed-language output.

SMI files are most commonly found on Korean video platforms (Naver TV, KakaoTV, Korean broadcasting sites), in older Windows Media Player content, and in educational CD-ROM materials.

Ready to convert your subtitles?

Drop your SMI file here and convert to SRT instantly.

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What is SMI?What is SRT?SRT vs SMI ASS vs SMI LRC vs SMI SBV vs SMI