Why Can’t a Movie Play in a Web Browser from Plex?

You may run into the issue where a movie can’t play in a Web browser when it is being streamed from Plex. There could be several issues, such as too much buffering or the movie won’t play in the browser at all.

You can have the latest PC parts in your computer, but for some reason the movie being streamed from a Plex Media Server won’t play. The main issue is not related to the hardware of your computer, but the software that is trying to play the move: your Web browser.

When building a Plex Media Server, the main concern comes down to what hardware to include in the server. More specifically, what CPU is going to be installed. The same can be said for a Plex player – what hardware will be used?

When it comes to streaming a video file to a computer, the software used to stream the video file also plays a role in how well the video file is played.

Why Can’t a Movie Play in a Web Browser from Plex?

Why a movie won’t play in a Web browser?

When playing a video file from Plex through a Web browser the main thing to consider is the video compatibility with the Web browser. Any modern computer will have no issues playing most, if not all, video formats if the proper codec is installed. The Web browser, though, only supports a specified number of video codecs.

This is where the issue lies. If a video file that you are trying to stream is encoded using HEVC (H.265), then most Web browsers won’t be able to play the video file natively. That is because only a small number of Web browser have support for that code.

If you try to play a H.265 video file, then the Plex server will need to transcode the file before sending it to the Web browser. This can easily cause the server CPU usage to spike to 100%, which can cause buffering on the client if the server can’t transcode fast enough.

Another issue can occur if the server has disabled transcoding. In this case, the server won’t transcode the movie file, and will instead send the move as is. Since the Web browser doesn’t support that video codec, the movie won’t play in the Web browser.

You can read about what video codec support is available for various browsers from HTML5 video - Wikipedia.

So how can you solve this issue? Let’s have a look at various options.

Solutions for playing a movie in a Web browser from Plex

There are a few solutions that can be used to allow a movie to play in a Web browser. Many of the solutions, though, can only be done by the owner of the Plex Media server.

1. Provide multiple encoded versions of the same movie.

This option is probably the simplest – although it requires more drive space. The owner of the Plex Media Server can store multiple encoded versions of the same movie. This will allow Plex to select the best version of the movie to send to the client. For example, you can have H.265 and H.264 versions of the same movie on your Plex server. Plex would use the H.264 version when the movie is streamed from a Web browser.

You can read about how to create and store multiple encoded versions for a movie in the post: How to Avoid Transcoding.

2. Don’t disable transcoding.

By default, Plex doesn’t disable transcoding, but it is a setting that a Plex server owner can enable. There could be a variety of reasons why a server owner would disable transcoding, however, it is not enabled for a reason.

By disabling transcoding, some clients could have issues with streaming movie files of the client doesn’t support the movie file encodings. If you are thinking of disabling transcoding on your server, the better option would be to look at option 1 above.

3. Use a native Plex application instead of a Web browser.

This option does require you to stop using a Web browser for streaming from a Plex Media Server. While it is very convenient to stream from a Web browser, there are Plex applications for most streaming platforms. The best part is that by using a Plex app, you can take full use of the hardware available to your streaming device.

The above provided three solutions to ensuring your can stream a movie from a Plex Media server to your Web browser. The key takeaway is to ensure the video codec that was used to encode the movie’s video stream is compatible with your Web browser. If it isn’t than you can see about using one of the solutions provided above.