YT Levelr

Tracking since May 14, 2026.

Changelog

• May 20, 2026
  description

  An extension that automatically equalizes the volume of YouTube videos, especially podcasts where every producer has their own idea of what the correct levels should be.
  
  Features
  
      Automatic Loudness Normalization: Automatically adjusts audio levels between videos to create a consistent listening experience
      Smart Gain Management: Uses asymmetric gain limits (more aggressive cuts than boosts) to prevent sudden loud blasts
      Confidence-Based Adjustment: Gradually widens gain range over 30 seconds as confidence in measurement grows
      Drift Correction: Slow automatic correction every 3 minutes after lock to handle long-term level shifts
      Noise Floor Protection: Ignores silence periods to avoid skewing measurements
      Local Processing Only: All audio processing happens entirely within your browser - no data is collected or transmitted
  
  How It Works
  
  YT Levelr uses the Web Audio API to intercept audio output from YouTube's video element and applies automatic gain correction:
  
      Audio Interception: Creates a source node from YouTube's video element
      RMS Measurement: Continuously measures Root Mean Square (RMS) amplitude of the audio
      Gain Calculation: Compares measured level against your target level (default: -22 dBFS)
      Smooth Transitions: Applies gain changes with asymmetric attack/release times to protect against sudden loud sounds
      Locking: After 30 seconds, gain locks and only drift correction applies
  
  Strategy Details
  
      Gain Limits Widen Over Time:
          0s: ±6dB/+3dB (immediate, low confidence)
          10s: ±12dB/+6dB
          30s+: ±20dB/+15dB (full range, locked)
  
      Asymmetric Treatment: Cuts are permitted more aggressively than boosts because a sudden loud blast is worse than staying quiet for a few seconds
  
      Gain Transitions: Faster transitions for cuts (0.15s) than boosts (1.2s) to protect against sudden loud audio
  
  Visual Indicators
  
  The popup displays real-time information:
  
      Applied Gain: Current gain multiplier being applied
      Status: Shows measuring, locked, or disabled state
      Confidence Bar: Progress toward full confidence (100% at 30s)
      Waveform Display: Visual representation of audio levels with target line

  An extension that automatically equalizes the volume of YouTube videos, especially podcasts where every producer has their own idea of what the correct levels should be.
  
  Features
  
  - Automatic Loudness Normalization: Automatically adjusts audio levels between videos to create a consistent listening experience
  - Smart Gain Management: Uses asymmetric gain limits (more aggressive cuts than boosts) to prevent sudden loud blasts
  - Gradual Confidence Growth: Gain limits start narrow and widen linearly until full adjustment range is available at 30s, allowing the algorithm to make small initial corrections before committing to its final decision
  - Drift Correction: Slow automatic correction every 3 minutes after lock to handle long-term level shifts
  - Noise Floor Protection: Ignores silence periods to avoid skewing measurements
  - Local Processing Only: All audio processing happens entirely within your browser - no data is collected or transmitted
  
  How It Works
  
  YT Levelr uses the Web Audio API to intercept audio output from YouTube's video element and applies automatic gain correction:
  
  - Audio Interception: Creates a source node from YouTube's video element
  - RMS Measurement: Continuously measures Root Mean Square (RMS) amplitude of the audio
  - Gain Calculation: Compares measured level against your target level (default: -22 dBFS)
  - Smooth Transitions: Applies gain changes with asymmetric attack/release times to protect against sudden loud sounds
  - Locking: After 30 seconds, gain locks and only drift correction applies
  
  Strategy Details
  
  - Gradual Confidence Growth:
    - Starts with narrow gain limits (±6dB/+3dB) at t=0 for cautious initial corrections
    - Limits widen linearly over time as confidence in measurement grows
    - At 30s, full range is available (±20dB/+15dB) and gain locks to its final decision
  
  - Asymmetric Treatment: Cuts are permitted more aggressively than boosts because a sudden loud blast is worse than staying quiet for a few seconds
  
  - Gain Transitions: Faster transitions for cuts (0.15s) than boosts (1.2s) to protect against sudden loud audio
  
  Visual Indicators
  
  The popup displays real-time information:
  
  - Applied Gain: Current gain multiplier being applied
  - Status: Shows measuring, locked, or disabled state
  - Confidence Bar: Progress toward full confidence (100% at 30s)
  - Waveform Display: Visual representation of audio levels with target line

• May 20, 2026
  permissions

  storage, activeTab, scripting

  storage, activeTab

Permissions & access

Permissions

storageactiveTab

Host access

None declared

Screenshots