The one setting that matters

Jellyfin apps have a video quality setting. Please leave it on Auto or the maximum setting — don't turn it down.

This sounds backwards, but here's why: the server sends you the original file as-is, and your device plays it directly. That's what makes the picture great. When an app asks for a lower quality, it forces the server to convert the video on the fly — which this server deliberately doesn't do. Turning quality down is the thing most likely to cause stuttering or errors.

Where to check it:

• TV / phone apps: Settings → Playback → set quality options to Auto or Maximum.
• Web browser: during playback, the gear icon → Quality → Auto.

If your internet connection genuinely can't keep up with a big 4K file, the fix is picking the regular HD version when one exists (see the next page), not lowering the quality slider.