Still works for any version of jellyfin 10.11.x, and also for the most recent versions of file transformation, however all work has been moved to Jellyframe
A Jellyfin plugin that lets you browse and apply community CSS themes from the server dashboard. Themes are injected at request time, your Jellyfin install is never modified on disk.
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- Jellyfin 10.11+
- File Transformation plugin
Both plugins are available from the repository below.
1. Add the plugin repository
In Jellyfin, go to Dashboard > Plugins > Repositories and add:
https://raw.githubusercontent.com/Jellyfin-PG/Repository/refs/heads/main/manifest.json
2. Install the plugins
Go to the Catalogue tab. Install File Transformation first, then Skin Manager. Restart Jellyfin after each install, or restart once after both.
3. Open the theme store
Navigate to Dashboard > Skin Manager in the sidebar. The default theme list loads automatically. Select a theme and click Save & Apply, then hard-refresh your browser (Ctrl+Shift+R).
As of version 1.2, themes can expose configurable variables that users can adjust without editing any CSS. When a theme supports variables, a ⚙ button appears next to the Select button on its card. Clicking it opens a popup where you can set values such as accent colors, font sizes, or toggle options. Changes take effect after clicking Save & Apply.
Theme authors declare variables in skins.json using a vars array. Each variable maps to a CSS custom property in the theme stylesheet, ACCENT_COLOR becomes var(--accent-color), FONT_SIZE becomes var(--font-size), and so on. See the theme repository for authoring documentation.
Themes are loaded from a separate JSON file hosted at:
https://raw.githubusercontent.com/Jellyfin-PG/Skin-Manager-Themes/refs/heads/main/skins.json
This file is fetched live, so new themes appear without a plugin update. To submit a theme, open an issue using the Theme Submission template in the theme repository.
When you select and save a theme, Skin Manager stores the configuration. On every request for index.html, the File Transformation plugin invokes a callback in Skin Manager which dynamically injects styling logic into the page:
- Server Themes: Skin Manager downloads the theme (and any enabled addons), strips out conditional logic, substitutes your customized variables in C#, and caches the fully compiled result to the local Jellyfin disk. It then injects a minimal stylesheet block pointing directly to a local offline API endpoint.
- User Themes: If enabled, users can select a personal theme from their individual settings menu. Their choices are saved inside their browser's local storage. Skin Manager injects a lightweight javascript payload that fetches the raw CSS from the server's local disk cache proxy, performs variable substitutions client-side, and injects the resulting stylesheet instantly.
In both paradigms, the original files on disk are never touched, and unreliable external CDN network requests are completely eliminated after the initial server-side cache download.
Removing a theme clears the stored URL and variables. The next page load returns to the default Jellyfin stylesheet.
1.5.3 — UI Stability & Fallback Reliability. Implemented synchronous variable injection to eliminate color flashing on page refresh. Refined isDashboard exclusion zones to protect User Preferences and Setup Wizard UI. Added automatic Server Theme fallback for users without a personal selection. Resolved a critical InvalidOperationException in the cache-clearing API by moving to manual administrator authorization.
1.5.2 — Preload Cross-Origin Normalization. Removed legacy CDN crossorigin="anonymous" preload declarations, correctly synchronizing HTTP request credential models with natively proxied .NET Server Theme endpoints beneath strict Cloudflare/Reverse-Proxy tunnels.
1.5.1 — Version-Bound Cache Matrix. Resolved static cache evasion by natively binding the offline disk proxy cache hashes directly to semantic JSON version strings ensuring automatic invalidation. Secured all frontend UI API config testing by rerouting them through the internal .NET backend. Implemented an explicit Clear Offline Cache manual override button securely authorized within the admin dashboard.
1.5.0 — Offline Disk Proxy & Dynamic Networking. Themes and addons are now downloaded and cached directly to your Jellyfin server's disk upon first load. Both Server and User themes are routed locally, rendering them completely immune to external CDN timeouts/outages and drastically improving startup times. Added dynamic preconnect injections for enhanced asset loading waterfalls.
1.4.2 — Resource Preconnecting. Injected dynamic preconnect headers for frequently accessed assets like Google Fonts and Imgur images to speed up external asset resolution.
1.4.1 — Preload Optimizations. Reordered stylesheet injection logic and implemented native <link rel="preload"> to prevent UI flickering while themes download.
1.4.0 — Per-User Themes. Administrators can now grant users the ability to override the global server theme and select their own localized skin from their Jellyfin settings menu.
1.3.4-1.3.7 — Stability & Quality of Life. Various minor bug fixes and user experience refinements across the plugin ecosystem.
1.3.3 — CDN Migration & CSS Gradients. Shifted target CDN endpoints for increased reliability and introduced dynamic gradient configuration bindings for theme creators.
1.3.2 — Cache Invalidation Fixes. Resolved edge-cases regarding stale cache persisting when rapidly switching between multiple server themes.
1.3.1 — Injection Performance Tuning. Optimized URL verification and drastically trimmed the computational overhead during CSS payload injection.
1.3.0 — Theme Versioning & Addon Engine. Implemented intelligent browser cache routing alongside semantic theme version tracking. Introduced the conditional addon engine, empowering users to compile modular stylesheets via variable toggles.
1.2.1 — Architecture Fixes. Addressed bugs surrounding dynamic CSS injection, internal plugin version mismatches, and configuration upgrade schemas.
1.2.0 — Dynamic Theme Variables. Engineered a realtime properties engine allowing themes to declare user-facing inputs on the Skin Manager dashboard. Users can configure variables like accent colors directly within the Jellyfin UI without touching CSS.
1.0.0 — Initial Release. The foundation of Skin Manager.
GPL-3.0
