A media player and organiser that scans your local libraries (local folders or mounted drives) and sorts everything into Movies, Shows, Anime and Music collections. It runs entirely locally, so there's no server to set up, and it can import an existing Plex database to bring your watch history across.
Music libraries are sorted into albums and artists using your files' tags, with album covers, artist photos and discographies pulled in from MusicBrainz.
It plays YouTube too, in the same player as everything else: your subscriptions and search, with no ads, and sponsor segments skipped by SponsorBlock. Between that and the libraries, pretty much everything we watch goes through Flex now.
It's also really fast. I got fed up with how sluggish Plex is on my TV PC, and this opens instantly and stays snappy even with tens of thousands of videos.
It's made to be used from the couch with a TV remote (arrows, OK and back are all you need), but a keyboard and mouse work fine too.
And it has plugins, for bolting on extras that don't belong in a media player. We wanted the LED strip behind our TV to glow with whatever's on screen, so the first plugin does just that, talking to the strip over Bluetooth with lotus-lamp-rs.
Download Flex from the releases page:
- Windows: run the
windows-x64-setup.exeinstaller, or unzip thewindows-x64.zipanywhere and runflex.exe. Everything it needs is included, so you can copy the folder to whichever PC is plugged into your TV. - Linux: unpack the
linux-x64.tar.gz, install libmpv from your distro (apt install libmpv2on Debian and Ubuntu) and runflex. To use a remote's media buttons, add yourself to theinputgroup. - Mac: there's no download yet, so you'll need to build it yourself.
To build Flex from source, see BUILDING.md.
Once it's running:
- Open Settings and add your libraries, picking whether each is Movies, TV, Anime or Music.
- If you want posters, descriptions and episode names, get a free API read access token from TMDB and paste it into Settings. Music is matched on MusicBrainz, which doesn't need a key.
- If you're coming from Plex, use "Import from Plex…" and point it at your
com.plexapp.plugins.library.db.
If something gets matched to the wrong show or album, open it and pick "Match online…" (or "Folders & seasons…" for shows) to fix it.
If you run Flex on more than one machine (say the TV and a projector), they can share what you've watched: Settings → Sync with other devices, then pick a folder they can all reach, like a folder on your NAS. Each Flex keeps its own libraries (pointing at wherever the media is on that machine, as long as the libraries have the same names) and they swap watched state, resume points, history, the watchlist, matches you fixed by hand and YouTube subscriptions and what you've watched there through that folder every 30 seconds or so.
Switch it on in Settings → YouTube and a YouTube card appears on Home. Flex fetches yt-dlp (and Deno, which yt-dlp needs for some of YouTube's checks) into its data folder by itself, and keeps them up to date, since YouTube changes things a lot and a newer yt-dlp is usually the fix.
Add channels under Channels by pasting a link or an @handle, or import your existing
subscriptions from Google Takeout (subscriptions.csv), FreeTube, NewPipe or an OPML
file. New videos are picked up from each channel's feed every half an hour (or press
Refresh), so there's no API key to set up. The Showing button switches between all your
channels, just the focused ones, and for you: suggestions made from the related videos
of what you've played lately and your subscriptions' new videos, leaving out anything
you've watched. Search works too, either on the YouTube page or from the main search
(pick the YouTube scope at the top of the results). History lists the videos you've
played, most recent first.
Videos take a few seconds to start, since yt-dlp has to ask YouTube for them first, but Flex starts on whichever video you have highlighted, so it's usually ready by the time you press OK. Hold OK on a video to mark it watched, see related videos or jump to its channel. Settings → YouTube also has the quality limit (1080p unless you change it), an H.264 option for machines that struggle to decode VP9, whether to show Shorts (hidden by default) and which SponsorBlock categories to skip (sponsors, self-promotion and "like and subscribe" reminders by default).
Both are off until you switch them on in Settings → Picture, and then every video library uses them unless you switch them off in that library's options.
- Anime4K upscaling (Anime4K, bundled with Flex) sharpens lines when lower-resolution video is shown on a bigger screen. It's made for anime but works on anything. Fast suits most GPUs; high quality needs a strong one.
- 60fps smoothing uses SVP if you have it installed: Flex plays through SVP's own copy of mpv and SVP adds the extra frames, so keep SVP running. Switch it on and restart Flex once. If SVP isn't installed, Flex says so and leaves it off. F2 while playing shows whether SVP has picked the video up.
YouTube videos get neither.
Settings → Theme changes how Flex looks. As well as the usual dark look, there are a few for fun, mostly after games and old computers we like: Final Fantasy VII's blue windows and pointing hand, Old School RuneScape's stone pillars and parchment chatbox (and Brick, its brown bevels on a stone wall), Pokémon's text boxes, Windows 95 and XP, early Mac OS X, a green-on-black hacker terminal with code raining down, TempleOS, and Maisy's farm, with hens and runner ducks by the pond. Everything is drawn by Flex; no pictures are taken from the games.
 Dark (default) |
 Final Fantasy VII |
 Old School RuneScape |
 Brick |
 Pokémon |
 Windows 95 |
 Windows XP |
 Aqua |
 Terminal |
 TempleOS |
 Maisy's Farm |
A theme is a small TOML file of colours and styles, so making your own is mostly a
matter of copying one and changing the colours. Custom themes go in the themes folder
in Flex's data folder (Settings → Theme → "Open themes folder") and can bring their own
background picture, pointer and font. See THEMES.md.
Plugins live in a plugins folder, either next to flex.exe (releases come with the
LED strip one) or in Flex's data folder (Settings → Plugins → "Open plugins folder").
Every plugin is off until you switch it on in Settings → Plugins, and one that's off
never runs, so they cost nothing if you don't use them. cargo build --release --workspace builds the plugins in this repo along with Flex.
For the LED strip, switch on "LED strip (Lotus Lamp)" and press play. It connects to the first strip it finds and remembers it; "Find strips" lets you pick another. Settings → Ambient light chooses between the whole picture and just its edges, how smoothly it changes, how vivid and bright it is, and what it shows when you're not watching anything (a dim warm white unless you change it). Press F2 during a video to see the colour being sent.
There's also a Trakt plugin, which keeps your Trakt history up to date with what you watch: switch it on, choose "Connect to Trakt" and enter the code it shows at the address it gives (auth.trakt.tv/activate) on your phone.
The AniList plugin keeps your anime list up to date: once you're 80% through an episode in an Anime library, the show's progress moves on to it (never back), and it's marked completed after the last episode. It finds each show on AniList by title and year, then follows AniList's sequels for later seasons (and into "Part 2" entries when episode numbers run on). To sign in, switch it on, choose "Sign in to AniList" (it opens AniList in a browser on the PC), approve Flex and paste the token AniList shows into Token. Tokens last a year; the plugin says when one is about to run out.
Flex works out the colour itself and only samples the screen while a light plugin is running, so a plugin for a different kind of light only has to pass it on. A plugin is just a program that reads and writes lines of JSON, so you can write one in whatever you like. See PLUGINS.md.
Arrows to move, OK to select, Back to go back. Hold OK for more options, and hold Back to quit. Play/pause, stop and next/previous work if your remote has them, and on my remote zoom+ toggles fullscreen and zoom- jumps to search.
While a video plays, OK pauses, Left/Right skip back and forward 10 seconds (30 while held), Up changes the subtitles and Down the audio track. Holding Up turns subtitles off, for when there are dozens of tracks to cycle back through. Each show remembers its own subtitle choice (a new show starts with the last one you picked) and audio track. Until you change it, the audio is in the show or film's original language when the file has it (anime in Japanese, say), going by TMDB; a library's options can switch that to the file's own default. F2 shows playback stats.
Switch on Settings → Web access, then open the address it shows on your phone and tap 📺 Remote. It has the remote's buttons (plus play/pause, the computer's volume, which repeats while held, and "subtitles off"), shows what's playing, and searches like the TV does, one scope at a time (Movies & shows, each library, Episodes, and YouTube when it's on): tap an episode or video and it plays on the TV. Show pages in the web UI get a 📺 button on each episode too. Anyone on your home network can use it, as with the rest of the web UI.
It can be installed as an app, so it gets its own icon and opens without the browser's bars. Chrome only installs apps from secure (HTTPS) addresses, and Flex's address on your home network isn't one, so on Android tell Chrome to trust it, once:
- In Chrome, open
chrome://flags/#unsafely-treat-insecure-origin-as-secure. - Enter Flex's address, e.g.
http://192.168.1.20:8484, set the flag to Enabled and relaunch Chrome. - Open that address, then ⋮ → Add to home screen → Install.
Without the flag, Add to home screen still makes a shortcut, but it opens in a normal Chrome tab.
Firefox for Android only installs web apps from HTTPS addresses and has no such flag, so install it with Chrome even if you use Firefox otherwise: the installed app runs on its own, whichever browser is your default.