If you're satisfied with Jellyfin, you should stick to that cause Plex ain't bringing much to the table in all honesty. I still use Plex cause it works better most of the time really.

Kodi has fallen out of fashion these days but it's also an excellent solution, depending on your streaming needs. I've used Plex in the past and found it to be sluggish on Samsung's Tizen OS. Jellyfin was a lot slicker, but also a fair bit more work to set-up if you want to stream remotely.

In the end, I put one of my pi4s to work as a Kodi box, since I only stream to my TV. It's running LibreELEC, which is a barebones OS providing just enough to run Kodi. Media is fetched from a samba share on the home server. It's been far better for me than Plex ever was, and way easier to set-up than Jellyfin. Kodi is essentially a standalone player, so not the right solution if you're wanting to stream to multiple devices or remote clients. Just throwing another option out there for anyone looking.

What are the main advantages to plex?

AFAIK they offer more apps resp. apps for more platforms. Apart from that, nothing really. Maybe a little more idiot-proof.

I have both (they both can coexist peacefully on the same library). I use jellyfin for any watching on my phone or computer.

However, where jellyfin still really kind of falls apart is when casting to my Chromecast. Controls don't work, subtitles are unpredictable or missing, and it's just generally a mess.

So I use Plex for casting, and jellyfin for everything else. I bought a Plex lifetime pass ages ago, so it's an easy call to just have them both running.

I like Jellyfin quite a bit better. The UI is less cluttered and the controls make more sense. It also doesn't phone home like plex. I do keep plex running beside it for my dad and sister. Plex has way better device support.

I personally use jellyfin and it works well enough for me to watch my movies and shows. I don't use the app but just use the browser but there are plugins for kodi and various apps too.

Ive not used Plex myself and from what I have read it does the job too. A few friends use it and are happy. I read recently they let go of 20% of their staff.

For me it comes down to it like this: do I want a company to have control over my viewing experience with closed source software or do I want a community FOSS experience under my control. That is very important to me but it depends on your own needs.

https://www.rapidseedbox.com/blog/jellyfin-vs-plex

Plex is great if you want to pay for features and need a media server/streaming platform hybrid

Jellyfin if you do not like being spied on by your self hosted media library. Plex if you do like being spied on by your self hosted media library.

Also - Plex if you want Audiobooks, because the app Prologue is 🔥

My experience with Jellyfin have not been great. The mobile app is just not working well enough

Plex has lots of customisation available (which I prefer) but is a little harder to get running in my experience. I'd say, install them both and see what you like most. Do start with Jellyfin as it's easy to install.

The FOSS crowd will eventually pop in and try sway you strongly the other way, but at the end of the day, it really boils down to bigger platform, more app choices and more supported platforms. If you expect anyone other than yourself to be using it, on anywhere else other than your own equipments, but just don’t quite know who or where yet, then Plex might give you a better running chance in supporting that use case. Otherwise, choose whichever one floats your boat more.

one main question should also be, do you want to selfhost or not.

because plex is not selfhosted imo due to their login servers.

I use Plex for (1) home library, (2) Live TV (HDHomerun), and (3) music (PlexAmp).

(1) Jellyfin is just as capable for home streaming of my home library.
(2) It would take approximately 15 seconds to show my live TV when I switch stations. Plex is almost instant and Plex has ad supported channels similar to a PlutoTV, et. al. I watch Scripps News and NBC Now along side my locals.
(3) There simply is no app as good as PlexAmp.

Finally, setting up Plex for outside access was dead simple, Jellyfin takes some effort.

Pour que no dos?

The antenna and music support is better on Plex imo, but I think both require to pay for premium

It depends what you use it for.

If you're watching your own content within your home then Jellyfin is better. It's free, open source and private. Your Jellyfin instance is yours and secure, and entirely under your control.

Plex's differences are mostly behind it's plex pass pay wall, and you sacrifice privacy using their platform. The key difference is really offline and remote viewing of content which is easier and slicker with plex (but doable with jellyfin), and the plex App maybe available a few more devices. There are also some credits and ad skipping features. That's about it - I struggle to see the benefit in plex. The only other thing I can think of is some people prefer the interface?

I used to use Plex and got annoyed when I couldn't view my content, which I host locally, because their login servers were down. Made me realise why did I need them so I researched a bit and switched to Jellyfin.

Jellyfins OTA and DVR are a dumpster fire. So if you want to watch and record OTA TV go with Plex.

A good middle ground is emby. I've been using it for a couple years now and it's been solid.

Plex for sharing with others. Jellyfin for personal use only.