SpecterJS

Privacy Fingerprint Shield for Chromium based browsers.

Protection vectors

Surface	Hooked API	Mitigation
2D Canvas	HTMLCanvasElement.toDataURL, toBlob	Shifts exported RGB channel values deterministically per navigation seed before encoding
WebGL GPU	WebGLRenderingContext, WebGL2RenderingContext	Masks unmasked vendor (0x9245) and renderer (0x9246) strings and perturbs float vertex buffers
Web Audio PCM	AudioBuffer.prototype.getChannelData	Applies deterministic sub-audible sample offsets (±5e-8) across channel buffers
DOM Bounding Boxes	Element / Range getBoundingClientRect	Adds sub-pixel micro-offsets (1e-5..9e-5 px) while preserving native DOMRect instances
Font Metrics	HTMLElement.prototype.offsetWidth, offsetHeight	Alters layout readouts once rapid font-probing thresholds (> 300 queries) are reached
Viewport Geometry	window.screen.availHeight	Derives a session-scoped pixel offset from the active viewport width
CPU Concurrency	Navigator.prototype.hardwareConcurrency	Clamps reported logical processor counts to standard buckets (2, 4, 8)
Media Enumeration	MediaDevices.prototype.enumerateDevices	Scrubs hardware label, deviceId, and groupId fields from returned descriptors
Battery Telemetry	Navigator.prototype.getBattery	Resolves a static full-charge stub (level: 1, charging: true)
Browser Plugins	Navigator.prototype.plugins	Returns a frozen empty plugin collection (length: 0)
HID Gamepads	Navigator.prototype.getGamepads	Returns a frozen empty controller array
WebRTC Peers	window.RTCPeerConnection	Wraps peer connection construction via Proxy and records origin telemetry

Installation

1. Clone the repository:

   git clone https://github.com/rizzn/SpecterJS.git

2. Open chrome://extensions/ in any Chromium browser and enable Developer mode.
3. Click Load unpacked and select the extension/ folder.

License

Licensed under the Apache License, Version 2.0 (LICENSE).