Plex Subtitles: How to Add, Sync, and Fix Subtitle Issues
Subtitles in Plex should just work. When they don’t, here’s every fix you need.
Types of Subtitles
- Embedded (SRT in MKV): contained inside the video file. Plex reads them automatically. No extra files needed
- External SRT: separate .srt file next to the video. Must be named identically:
Movie (2024).srtforMovie (2024).mkv - PGS/VOBSUB (image-based): common in Blu-ray rips. These FORCE transcoding because they must be burned into the video stream. Avoid if possible
- ASS/SSA (styled): common in anime. Support colors, positioning, and effects. Also force transcoding in most cases
Adding External Subtitles
Place the .srt file in the same folder as the video with the same name. For language codes, use: Movie (2024).en.srt for English, Movie (2024).es.srt for Spanish. Refresh metadata in Plex after adding.
Fixing Sync Issues
Subtitles out of sync? Try these:
- Plex subtitle offset: during playback, click the speech bubble icon > Subtitle Offset. Adjust +/- until it matches
- SubSync tool: free software that auto-syncs subtitles to audio. Drop in your video and subtitle, it outputs a synced version
- Download a different version: OpenSubtitles and Subscene often have multiple versions for different releases
Automatic Subtitle Downloads
Bazarr is the standard tool. It monitors your Plex library and automatically downloads matching subtitles from OpenSubtitles, Subscene, and other sources. Configure your preferred languages and quality thresholds, and it handles everything.
Avoiding Transcoding
If subtitles force your server to transcode, convert image-based subs (PGS/VOBSUB) to SRT using SubtitleEdit or Subtitle OCR. SRT subtitles can be overlaid by the client without transcoding.
Quick rule: SRT = good (no transcode). PGS/ASS = expensive (forces transcode). When possible, always use SRT.