Saskatoon

A Firefox extension born out of pure frustration.

I was binge-watching a series on Disney+ and every single time an episode ended, I had to:

1. Click "Next Episode"
2. Re-enter fullscreen because Disney+ kicks you out of it
3. Turn my subtitles back on because those get reset too

Every. Single. Episode.

After the 15th time doing this dance, I snapped and built Saskatoon. Now I just hit play and don't touch my keyboard until the season is over.

What It Does

• Auto-clicks "Next Episode" — Detects the end-of-episode overlay and clicks through instantly so playback continues without interruption.
• Re-enters fullscreen — Disney+ drops you out of fullscreen between episodes. Saskatoon puts you right back in, automatically. It clicks Disney+'s own fullscreen button (via shadow DOM) so the player controls still work properly.
• Re-enables subtitles — If you had subtitles on, they stay on. Saskatoon remembers your subtitle language and re-applies it after each transition.

Install

Get Saskatoon on Firefox Add-ons

One-Time Firefox Setup (for auto-fullscreen)

A setup guide will open automatically on first install. The short version:

1. Go to about:config in Firefox
2. Search for full-screen-api.allow-trusted-requests-only
3. Toggle it to false

This allows Saskatoon to programmatically restore fullscreen without requiring a click. Without this, Firefox blocks all programmatic fullscreen requests for security reasons.

Then just head to Disney+, start a series, enter fullscreen, and let Saskatoon handle the rest.

Settings

Click the Saskatoon icon in your toolbar to toggle features on/off:

Setting	Default	Description
Auto Next Episode	On	Automatically clicks "Next Episode"
Re-enter Fullscreen	On	Restores fullscreen after transitions
Re-enable Subtitles	On	Keeps your subtitles on between episodes
Subtitle Language	Auto-detect	Which subtitle track to re-enable

How It Works

Saskatoon uses a belt-and-suspenders approach to detect episode transitions:

• MutationObserver watches the DOM for the "Up Next" button appearing (primary)
• Polling checks every second as a fallback
• Video ended event catches the end of playback directly

For fullscreen restoration, it clicks Disney+'s own <toggle-fullscreen> web component (inside its shadow DOM) rather than calling requestFullscreen() directly. This ensures the player's internal state stays consistent and controls work normally on hover.

Subtitle state is tracked via the HTML5 TextTrack API near the end of each episode, then re-applied after the transition using Disney+'s subtitle picker UI.

Files

saskatoon/
├── manifest.json    # Extension manifest (Manifest V2)
├── content.js       # Core logic — injected into disneyplus.com
├── background.js    # Handles window-level fullscreen + first-run setup
├── popup.html       # Settings popup UI
├── popup.js         # Settings persistence
├── setup.html       # First-run setup guide (full page)
├── setup.js         # Setup page interactions + confetti
└── icons/
    ├── icon-48.png
    └── icon-96.png

Why "Saskatoon"?

No reason. It's just a fun word.

License

MIT