How to Extract PGS (SUP) with MKVToolNix and Convert to SRT
In MKVToolNix GUI, open your MKV file, select the PGS subtitle track labeled S_HDMV/PGS, and extract it as a .sup file. Then upload the .sup file to this converter for OCR processing.
- Upload your SUP (PGS) file
- Select subtitle language
- Click Convert
- Download your SRT file
Extract PGS (SUP) Subtitle Tracks with MKVToolNix
Finding PGS Tracks in MKVToolNix GUI
Open MKVToolNix GUI and add your MKV file. In the Tracks panel, subtitle tracks in PGS/SUP format appear with codec "S_HDMV/PGS". Each track shows its language tag (e.g., "eng", "spa", "jpn") and track name if set by the file creator.
Check the PGS track you want to extract. Deselect the video and audio tracks — you want subtitle-only output. Set an output filename ending in .sup for the extracted subtitle file. MKVToolNix writes the PGS stream to a standalone .sup file.
Command-Line Extraction with mkvextract
For command-line users: mkvextract tracks movie.mkv TID:subtitle.sup where TID is the track number shown by mkvinfo movie.mkv. Track IDs in mkvextract start at 1, not 0.
To extract multiple PGS/SUP tracks at once: mkvextract tracks movie.mkv 3:eng.sup 4:spa.sup. Each track ID maps to a separate output file.
Convert SUP to SRT After MKVToolNix Extraction
Upload the .sup File to This Browser Converter
The .sup file from MKVToolNix is the complete PGS stream. Upload it here, select the matching OCR language (check the track's language tag in MKVToolNix if unsure), and click Convert. The browser reads the PGS image data using Tesseract OCR and produces a standard SRT file.
The resulting SRT is ready for Plex, Jellyfin, VLC, or any subtitle editor. Timing is preserved exactly from the PGS stream metadata.
Naming Your SRT for Media Servers
For Plex and Jellyfin, name the SRT file using the pattern: video_filename.language_code.srt — for example, movie.en.srt for English or movie.ja.srt for Japanese. Place it in the same folder as the video file and trigger a library scan.
MKVToolNix Subtitle Workflow
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Convert Your SUP (PGS) File to SRT Now
Upload the .sup file extracted by MKVToolNix and get SRT instantly. No account, no installation, no upload to any server.
Frequently Asked Questions
Can MKVToolNix extract PGS subtitles from M2TS or Blu-ray disc files?
MKVToolNix works primarily with Matroska files. For M2TS and Blu-ray disc structures, use FFmpeg or MakeMKV to get a .mkv first, then use MKVToolNix to extract the PGS/SUP track.
What is the track ID format in mkvextract?
Track IDs in mkvextract are integers starting at 1. Use mkvinfo movie.mkv to see track IDs. Subtitle tracks appear as "Track type: subtitles" with their ID number.
Does MKVToolNix GUI show the language of each PGS/SUP subtitle track?
Yes. Language tags appear in the Tracks panel. If a track shows "und" (undefined), the MKV was not properly tagged during creation. You can still extract and convert — just select the correct language manually in the OCR step.
Is MKVToolNix free for extracting PGS and SUP files?
Yes. MKVToolNix is free, open-source software available for Windows, macOS, and Linux. It requires no registration or purchase to use the extraction features.