Universal Audio Boost Slider

WHAT IT DOES

Universal Audio Boost Slider lets you amplify the volume of any HTML5 audio or video element beyond the browser's maximum 100% limit. Using the Web Audio API's GainNode, the extension boosts audio levels up to 400%, making quiet videos, podcasts, and audio files clearly audible. A floating slider overlay provides real-time control, with presets for common boost levels and keyboard shortcuts for quick adjustments. The extension automatically detects all media elements on the page, including those loaded dynamically, and applies boost settings instantly. A built-in safety limiter prevents distortion and clipping, ensuring clean audio even at high boost levels. Boost preferences are remembered per media source and per domain, so your settings persist across sessions.

WHERE IT RUNS

The extension works on every website with HTML5 video or audio elements, including streaming platforms, online learning portals, podcast players, video conferencing tools, social media sites, and any other page with embedded media content. It runs locally in your browser, applying gain adjustments directly to the media elements without modifying the page's core functionality. The extension supports all major browsers and adapts to both desktop and mobile viewports seamlessly.

HOW TO USE

After installation, a floating "🔊 Boost" button appears on the page when media is detected. Click it to open the audio boost overlay. Use the slider to adjust the boost level continuously from 0.1x to 4.0x (10% to 400%). Click preset buttons (0.5x, 0.75x, 1x, 1.25x, 1.5x, 2x, 2.5x, 3x, 4x) for quick selection. Use the "+0.1" and "-0.1" buttons for fine adjustments, or "Reset" to return to 1x. When the overlay is open, keyboard shortcuts are active: press "+" or "=" to increase boost by 0.1, "-" to decrease by 0.1, "R" to reset to 1x, and "Escape" to close the overlay. The overlay displays the current boost level and the active media source. A toggle in the settings panel enables or disables the safety limiter to prevent clipping.

THE ACTUAL MECHANISM — WEB AUDIO API GAIN NODE WITH DYNAMICS COMPRESSOR

The extension leverages the Web Audio API to control audio gain. For each media element, the extension creates an AudioContext and uses `createMediaElementSource()` to connect the media to an audio processing graph. A GainNode is inserted in the signal chain with its `gain.value` property controlling the amplification level. When the user adjusts the slider, the GainNode's gain value is updated in real-time. To prevent distortion and clipping at high boost levels, the extension optionally inserts a DynamicsCompressorNode (limiter) after the GainNode. The limiter is configured with `threshold: -3dB`, `ratio: 20:1`, `knee: 0`, and fast attack/release times, which effectively caps the output level to prevent clipping while preserving the boosted signal. For media that cannot use the Web Audio API (due to CORS restrictions or cross-origin issues), the extension falls back to the media element's `volume` property, which is clamped to 1.0 (100%) but provides some boost capability. All boost preferences are stored using `GM_setValue` with cache keys derived from the media source URL and domain, enabling persistent per-source and per-domain settings.

THE PANEL

The settings panel is a lightweight, draggable overlay that appears in the center of your screen. You can reposition it by clicking and dragging the title bar; release it near the screen edge and it will snap into place automatically. To collapse the panel into a compact title bar, click the minimize button, expanding it again with the same control. The panel is fully responsive, adapting to different screen resolutions with a minimum width of 300px and a maximum of 480px. Press the Escape key at any time to dismiss the panel without applying changes. All controls—the show/hide/toggle overlay buttons, default boost setting, max boost limit, position selector, overlay visibility toggle, limiter toggle, shortcut input, and reset button—are accessible within a clean, high-contrast interface that respects your system's color scheme.

PLEASE NOTE

This extension requires the free BotGentz companion extension to be installed and active, which provides the underlying storage and overlay engine. The Web Audio API is subject to cross-origin restrictions—some media elements served from different domains may not be connectable to an AudioContext, in which case the extension falls back to the volume property. The safety limiter reduces the risk of clipping but cannot eliminate it entirely at very high boost levels. No personal data, browsing history, or audio content is ever collected, stored, or transmitted. All boost preferences are saved using the browser's storage API and remain solely on your device. The extension does not inject ads, trackers, or analytics of any kind.