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A browser extension for real-time audio compression, limiting, normalization, noise canceller and even subtitler / transcriber. Perfect for streaming sites where audio levels can vary wildly.

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ozankaraali/limitr

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Limitr

Limitr

A browser extension for real-time audio compression, limiting, EQ, and normalization.
Perfect for streaming sites where audio levels can vary wildly.

Simple Mode Active Exclusive Mode Advanced Mode

Features

  • Real-time audio processing using the Web Audio API
  • Simple & Advanced modes: Quick presets or full control over every parameter
  • 12 Audio Presets (lightest to heaviest):
    • Off — No processing (bypass)
    • Music — Light compression preserving dynamics
    • Lo-Fi — Warm & mellow sound
    • Stream Watch — Single-band compression for Twitch & YouTube
    • Podcast — Voice clarity and consistency
    • Voice Focus — Multiband compression + EQ optimized for speech
    • Movie — Compression + dialog EQ for action & dialog balance
    • Bass Tamer — Heavy compression with bass reduction
    • 90s TV — Warm CRT-style sound with noise, and optional TV+ visual mode
    • Night Mode — Comfy low-volume watching with scream frequency taming
    • Anti-Scream — Crushes all peaks (12:1 compression + scream EQ cuts)
    • Sleep — Fall asleep easy (heavy compression + treble cuts + volume reduction)
  • Single-band compressor with full parameter control (threshold, ratio, knee, attack, release)
  • 3-band multiband compressor with independent per-band threshold, ratio, and gain
  • 5-band parametric EQ with selectable filter types per band and live curve visualization
  • Brick-wall limiter with adjustable threshold and timing for peak protection
  • Noise gate with configurable threshold, hold, and release (Exclusive mode)
  • Bass & Treble Cut filters for additional frequency shaping
  • Background noise (white/pink/brown) for vintage audio effect
  • Gain reduction meter showing real-time compression activity
  • Collapsible sections with independent on/off toggles per processing block
  • Two processing modes: Regular (fullscreen-friendly) or Exclusive (multi-tab with AI features)
  • Exclusive mode extras: AI noise suppression (RNNoise), auto-gain (AGC), noise gate
  • No external dependencies (except RNNoise WASM for AI noise suppression)

Installation

Chrome Web Store

Coming soon

Chrome / Chromium-based browsers (Manual)

  1. Open chrome://extensions/
  2. Enable "Developer mode" (toggle in top right)
  3. Click "Load unpacked"
  4. Select the limitr folder

Firefox

  1. Open about:debugging#/runtime/this-firefox
  2. Click "Load Temporary Add-on"
  3. Select any file in the limitr folder (e.g., manifest.json)

Note: For permanent Firefox installation, the extension needs to be signed or installed via about:config with xpinstall.signatures.required set to false.

Usage

  1. Click the Limitr icon in your browser toolbar
  2. Toggle the master switch to enable/disable processing
  3. Select a preset or switch to Advanced mode for full control
  4. Each processing section (Compressor, Gain, EQ, Limiter, Filters, Effects) can be independently toggled on/off and collapsed
  5. The gain reduction meter shows real-time compression activity

Advanced Parameters

Compressor

Parameter Range Description
Threshold -60 to 0 dB Level above which compression begins
Ratio 1:1 to 20:1 Amount of compression applied
Knee 0 to 40 dB Smoothness of compression onset
Attack 0 to 100 ms How quickly compression engages
Release 10 to 1000 ms How quickly compression releases

Gain

Parameter Range Description
Makeup Gain -24 to +24 dB Volume adjustment after compression
Output Gain -24 to +24 dB Final volume adjustment (master)

5-Band Parametric EQ

Parameter Range Description
Frequency 20 to 20000 Hz Center frequency per band
Gain -12 to +12 dB Boost/cut per band
Q 0.1 to 10 Bandwidth (narrow to wide)
Type Highpass/Lowshelf/Peaking/Highshelf/Lowpass Filter shape per band

Limiter

Parameter Range Description
Threshold -30 to 0 dB Ceiling above which audio is brick-wall limited
Attack 0 to 50 ms How quickly the limiter engages
Release 10 to 500 ms How quickly the limiter releases

Multiband Compressor

Parameter Range Description
Crossover 1 20 to 500 Hz Split point between sub and mid bands
Crossover 2 500 to 10000 Hz Split point between mid and high bands
Band Threshold -60 to 0 dB Per-band compression threshold
Band Ratio 1:1 to 20:1 Per-band compression amount
Band Gain -12 to +12 dB Per-band output gain

Filters

Parameter Range Description
Bass Cut (Highpass) 0 to 300 Hz Removes frequencies below this value
Treble Cut (Lowpass) 2000 to 22050 Hz Removes frequencies above this value

Effects

Parameter Range Description
Noise Level 0 to 30% Background noise amount
Noise Type White/Pink/Brown Noise character (harsh to cozy)

Exclusive Mode Only

Parameter Range Description
AI Noise Suppression On/Off RNNoise-based background noise removal
Auto-Gain (AGC) On/Off Automatic level control
AGC Target -30 to 0 dB Target loudness for auto-gain
Noise Gate On/Off Silence noise in quiet sections
Gate Threshold -80 to -20 dB Level below which audio is gated
Gate Hold 10 to 500 ms How long the gate stays open after signal drops
Gate Release 10 to 500 ms How quickly the gate closes

How It Works

Signal Chain

Source → [Compressor OR Multiband] → [Pre-Limiter] → [Noise Suppression] → [Bass Cut] → [5-Band EQ] → [Treble Cut] → [Auto-Gain] → [Noise Gate] → [Limiter] → Output Gain → Destination

Each block in brackets is optional — only wired into the chain when its toggle is enabled. The compressor and multiband compressor are mutually exclusive (enabling one disables the other).

Processing Modes

Regular Mode (fullscreen compatible):

  • Injects a content script that uses MediaElementSource to process audio
  • Scans for all <video> and <audio> elements
  • Works in fullscreen video playback
  • Supports: Compressor, Multiband, EQ, Limiter, Filters, Gain, Effects

Exclusive Mode (multi-tab with AI features):

  • Uses Chrome's tabCapture API to capture tab audio
  • Processes audio in an offscreen document
  • All Regular mode features plus: AI Noise Suppression (RNNoise), Auto-Gain (AGC), and Noise Gate
  • Note: Fullscreen may be restricted in this mode

Privacy

Limitr does not collect, store, or transmit any personal data. All audio processing happens locally in your browser. See Privacy Policy.

License

MIT - Ozan Karaali

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A browser extension for real-time audio compression, limiting, normalization, noise canceller and even subtitler / transcriber. Perfect for streaming sites where audio levels can vary wildly.

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