HoverTrailer

Bring your library to life: Instant trailer playback on hover for Jellyfin.

Preview

Configuration 1 - Centered Positioning, Background Blur, Higher Scaling, No Offset

Configuration 2 - Custom Positioning, No Blur, Lower Scaling, Custom Offset

▶️ Show Preview Videos

Configuration 1

Configuration 2

Manifest URL

https://raw.githubusercontent.com/Fovty/HoverTrailer/master/manifest.json

Recommended companion plugin: install File Transformation (v2.2.1.0+) first. HoverTrailer auto-detects it and injects the client script through it instead of modifying files on disk.

Features

Playback

• Netflix-style hover preview with configurable delay
• Multi-source trailer detection: local files, remote YouTube, and optional theme-video fallback
• Audio on/off with adjustable volume (muted during autoplay until the page has user activation — browser policy)
• Hover progress indicator on the card during the delay

Positioning modes

• Center — preview is centered in the viewport (default)
• Custom — preview is centered on the card with configurable offsets
• Anchor to Card — preview follows the card as the page scrolls (tethered)

Sizing

• Fit to Content (default) — matches the trailer's aspect ratio, scaled by a percentage you choose (50-1500%), clamped to 90% of the viewport
• Manual — fixed width and height in pixels
• Adjustable opacity and corner radius

Background blur

• Off / Full (uniform blur over the page) / Halo (dense blur right next to the preview, fading out over a configurable radius — hides distracting nearby posters without dimming the whole screen)

Behavior options

• Persistent preview — keep playing after the cursor leaves the card; dismiss with click, Escape, or by hovering a different card long enough for a new preview to start
• Focus trigger — keyboard/D-pad focus on a card triggers the preview (for Jellyfin Web in a TV browser or with spatial-navigation overlays). Mouse clicks don't re-trigger.

Installation

From Jellyfin Plugin Catalog (Recommended)

1. Open Jellyfin Admin Dashboard
2. Navigate to Plugins → Manage Repositories
3. Click + (Add) to add a new repository
4. Enter the Manifest URL:

   https://raw.githubusercontent.com/Fovty/HoverTrailer/master/manifest.json
   

5. Click Save
6. Navigate back to Plugins
7. Search for "HoverTrailer"
8. Click Install
9. Restart Jellyfin server to activate the plugin
10. Open Plugins → HoverTrailer → Settings to configure (every option has an inline description)

Manual Installation

1. Download the latest release from GitHub Releases
2. Extract the .dll file to your Jellyfin plugins directory:
   • Windows: %ProgramData%\Jellyfin\Server\plugins\HoverTrailer
   • Linux: /var/lib/jellyfin/plugins/HoverTrailer
   • Docker: /config/plugins/HoverTrailer
3. Restart Jellyfin server

Known limitations

• Touch devices: hover is a pointer-only gesture, so the plugin disables itself on phones and tablets (UA sniff + (hover: none)).
• Native mobile / TV apps: Jellyfin's native mobile and smart-TV apps don't load the web frontend, so the plugin has no effect there. Focus Trigger covers the Jellyfin-Web-in-a-TV-browser case.
• If audio is enabled, the first hover after a fresh page load still plays muted. Chrome and Safari block unmuted autoplay until you interact with the page once — click anywhere and all subsequent hovers have audio.
• YouTube iframe aspect ratio is hardcoded to 16:9. The YouTube iframe is cross-origin so the actual video aspect can't be read.

Troubleshooting

Trailers not playing

1. Check trailer availability — confirm the movie has a trailer URL or local trailer file in Jellyfin.
2. Enable Debug Logging and watch the browser console (F12) for [HoverTrailer] lines.
3. Audio: if you expect sound on the first hover, click anywhere in Jellyfin once to grant the page user activation.

Preview not showing

1. Confirm the plugin appears in the Jellyfin admin panel and is enabled.
2. Hard reload the page (Ctrl+Shift+R / Cmd+Shift+R) — the client script is cached by the browser.
3. Make sure you're on a desktop browser (phones and tablets skip the plugin by design).

Docker permission issues

If you see Access to the path '/usr/share/jellyfin/web/index.html' is denied, install the File Transformation plugin (see the recommendation under Manifest URL) — HoverTrailer will detect it and stop touching the web directory.

Manual alternatives if you can't use File Transformation

Fix file permissions:

docker exec -it jellyfin find / -name index.html
docker exec -it --user root jellyfin chown jellyfin:jellyfin /jellyfin/jellyfin-web/index.html
docker restart jellyfin

Or bind-mount the file:

docker cp jellyfin:/jellyfin/jellyfin-web/index.html /path/to/jellyfin/config/index.html
# then in docker-compose.yml:
volumes:
  - /path/to/jellyfin/config/index.html:/jellyfin/jellyfin-web/index.html

Development

git clone https://github.com/Fovty/HoverTrailer.git
cd hovertrailer
# StyleCop warnings are treated as errors in CI; suppress locally:
dotnet build --configuration Release --property:TreatWarningsAsErrors=false

Contributions welcome — fork, branch, PR. Match the existing code style, update docs alongside any configuration change, and test across browsers / Jellyfin versions.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments

• Jellyfin Team - For the excellent media server platform
• IntroSkipper Plugin - Architecture and CI/CD inspiration
• Jellyscrub Plugin - Configuration UI patterns

Support

• Issues: GitHub Issues
• Discussions: GitHub Discussions
• Jellyfin Community: Official Jellyfin Forums

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Note: This plugin is not officially affiliated with Jellyfin or Netflix. It's a community-developed enhancement for the Jellyfin media server.