ClearBoost — Volume Booster

ClearBoost is the safe, open-source tab volume booster: up to 600%, with no ads, affiliate injection, tracking, remote code, or hidden page access.

The extension uses Chrome's standard tab-capture and Web Audio APIs. Audio stays on the device. Returning a tab to 100% with Flat EQ and mute off tears down capture completely and restores Chrome's native audio path.

Trust model

• No ads, affiliate links, analytics, telemetry, external fonts, or remote code.
• No content scripts.
• No host permissions.
• No network requests while PAYMENTS_ENABLED is false.
• ExtPay 3.1.2 is the only vendored dependency and is sourced from the official Glench/ExtPay dist/ExtPay.js file.
• Pro features are free during launch.

Permissions

Permission	Why ClearBoost needs it
tabCapture	Captures audio from the user-selected tab for local volume and EQ processing.
storage	Stores temporary tab state and user-enabled per-site settings.
offscreen	Hosts the Web Audio graph while the popup is closed.
tabs (optional)	Requested only for per-site memory, to read a hostname and restore its saved level when audio begins.

Features

• Per-tab volume from 0% to 600%
• Mute, reset, and distortion prevention
• Flat, Bass Boost, Voice Clarity, and Treble EQ presets
• Optional per-site volume memory
• Keyboard commands that work while the popup is closed
• Independent state and cleanup for multiple tabs
• Designed errors for pages Chrome refuses to capture
• Light and dark popup themes

Architecture

background.js owns tab state, badges, commands, per-site memory, and capture lifecycle. offscreen.js owns one Web Audio graph per boosted tab. popup.js is a no-build vanilla interface that communicates with the service worker.

The graph is:

captured tab -> 3 BiquadFilter nodes -> DynamicsCompressor -> GainNode -> speakers

dumpState() is available in the service worker console for inspecting all tracked tabs.

Payments

PAYMENTS_ENABLED is currently false, so isPro() returns true and all Pro features are available during launch.

The intended paid offer is:

ClearBoost Pro — $2.99 once. No subscription. EQ presets + per-site volume memory.

When payments are enabled, the service worker uses the official vendored vendor/extpay.js client with the placeholder ExtensionPay ID clearboost.

Local development

There is no build step.

1. Generate icon PNGs when the SVG changes:

   .\tools\rasterize.ps1

2. In Chrome, open chrome://extensions, enable Developer mode, and choose Load unpacked.

3. Select this repository directory.

Keyboard shortcuts can be reviewed or customized at chrome://extensions/shortcuts.

Source and license

ExtPay is distributed under its own AGPL-3.0-or-later license. ClearBoost source code is available under the MIT License.