This month’s sponsored Plex video is all about subtitles—again. In prior videos, I’ve covered how to automatically download them through a Plex Pass feature and also how to manage subtitle files manually. But even with the right files in place, sometimes they just sync up properly with the video. This time, I took a look at three different ways to fix subtitle syncing issues.
First, there’s a simple manual offset option. If your subtitles are off by a few seconds, you can go into the playback settings on your Plex client and shift them forward or backward in 50 millisecond increments. It’s available on most platforms. Once there, you can fine-tune the delay until things match up—or hit reset if you went too far and start over.
The second method is a newer feature for Plex Pass users: automatic subtitle sync. This one’s more sophisticated, designed to handle issues like subtitle drift, where the timing gradually goes out of sync due to differences in video encoding (like 24p vs. 60p). It works by generating a voice print from the movie’s audio and trying to match it to the subtitle file. The server needs to be running version 1.41.0 or higher, on a 64-bit platform. It doesn’t work on some server versions, including the Nvidia Shield Plex Server (although the Shield client will work) and FreeBSD, but most modern 64-bit Windows or Linux setups are fine.
Setting it up requires enabling a few options. In the server settings under “Settings > Library,” you’ll need to turn on “Generate voice activity data.” Then, within each library (under “Manage Library > Edit > Advanced”), you enable voice activity detection individually. Once that’s done, Plex will start analyzing your media files and generating those voice prints. You can manually trigger this analysis per file, and it happens fairly quickly.
When everything’s in place, a new option to autosync subtitles appears in the playback settings. If the subtitle file’s timing is off in a consistent way, this feature can bring it back in line with the spoken audio. It doesn’t work for every situation, but when it does, it’s a nice hands-off solution.
Finally, if nothing else works, there’s always the DIY route. I used an open-source tool called Vibe to generate subtitles from scratch using the Whisper speech-to-text engine. It’s a local app, so everything runs on your computer without uploading anything to the cloud. You just drop in your media file, select SRT format, and it builds a transcript that you can tweak and then import into Plex. Because it’s based on the actual audio in your file, the results tend to line up much better than trying to force in a third-party SRT from somewhere else.
Between these three approaches—manual offsets, auto-sync, and Vibe—you should have a solid foundation for dealing with subtitle syncing issues in Plex. If you’ve got ideas for future Plex topics, I’d love to hear them.
Disclosure: This was a sponsored post from Plex, however they did not review or approve this content or my video before it was uploaded.