YTSpoofingStream

YTSpoofingStream is an open-source browser extension designed to deliver studio-grade Opus audio (ITAG 774 at ~256–301kbps with full frequency response >20 kHz) directly on YouTube Web.

By default, YouTube Web permanently caps desktop audio streams to ~160kbps Opus (ITAG 251) with a sharp 15–16 kHz cutoff, reserving higher-tier Opus 774 exclusively for mobile apps and Smart TVs—even for active YouTube Premium subscribers.

To bypass this without breaking YouTube's modern SABR/UMP chunk protocol, YTSpoofingStream employs a Dual-Stream Synchronization Engine:

• Untouched Video: The native video pipeline handles 4K/HDR/AV1 and DRM playback completely untouched. • Descriptor-Level Silencing: Silences the native video's physical audio output at the prototype descriptor level, keeping YouTube's native volume slider, shortcuts, and mute toggles fully functional. • Parallel Hi-Fi Engine: Streams authentic, deciphered ITAG 774 Opus in parallel, synchronized to video with sub-15ms precision. • Privacy-Friendly: Runs 100% locally client-side with zero tracking or telemetry.

Requirements: • An active YouTube Premium subscription (required by YouTube's backend to serve high-tier ITAG 774/141 streams).

Supported Browsers: • Chromium-based browsers (Chrome, Brave, Edge, Opera, etc..).