Free online SMI to TXT converter

A media player, editor, or transcription workflow may accept plain .txt files but not SAMI subtitles with the .smi extension. Converting extracts readable caption text for editing, searching, sharing, or archiving, with the option to retain timestamps as ordinary text.

What the SMI format is

SMI usually means SAMI (Synchronized Accessible Media Interchange), an HTML-like subtitle format developed by Microsoft. A SAMI file stores captions in elements such as <SYNC Start="5000">, where the Start value is a timestamp in milliseconds. HTML elements, CSS classes, metadata, line breaks, and language tracks may also be present.

SAMI is used by legacy Windows Media playback and authoring software, accessibility workflows, Korean subtitle collections, and other applications that support the format. One file can contain multiple language classes or versions of the same caption, so conversion may require selecting the intended language.

What the TXT format is

TXT is a plain-text file containing characters without a standard subtitle structure. It opens in basic text editors, is easy to search and revise, and is suitable for transcripts, translation, archiving, and workflows that cannot parse SAMI.

TXT does not define synchronization, styling, positioning, language tracks, or line-break behavior. A converter can write timestamps into the output as ordinary lines, but those timestamps are not machine-readable subtitle timing unless the receiving program defines a specific TXT convention.

How to convert SMI to TXT

The built-in converter on 101convert.com can process the file in a browser without installing software:

1. Open the SMI-to-TXT conversion page on 101convert.com.
2. Upload the .smi file.
3. Choose TXT as the output format and start the conversion.
4. Download the generated .txt file and open it in a text editor.

If the source contains several language tracks and the converter provides a language option, select the required track before starting. Otherwise, the output may contain multiple tracks or only the first track.

For a local Windows workflow, open the file in Subtitle Edit, confirm that SAMI was imported correctly, then use File → Export → Plain text or the equivalent plain-text export command. Select whether to include timestamps if the export dialog provides that choice, and save the result with a .txt extension.

Do not rename subtitle.smi to subtitle.txt. Renaming changes only the filename extension; the file still contains SAMI tags, timestamps, CSS markup, and possibly multiple language tracks.

Quality and compatibility limits

• Plain-text conversion removes SAMI styling, colors, positioning, speaker formatting, and synchronization semantics.
• Without exported timestamps, the result is a transcript, not a timed subtitle file. Keep the original SMI if synchronized playback may be needed later.
• SAMI files may use UTF-8, UTF-16, Windows-1252, or Korean encodings. Garbled characters or replacement symbols indicate an encoding mismatch; reopen the source with the encoding declared in its header when possible, then save the TXT file as UTF-8.
• Blank <SYNC> elements can mark the end of a caption rather than an empty subtitle. Review the output for duplicated language tracks, missing line breaks, leftover tags, and incorrectly decoded entities such as   or &.