Free Auto-Ducker & Sidechain Tool

Perfect for Podcasts & Voiceovers. Upload your voice track and background music,
and we will automatically lower the music volume whenever you speak.

Online Podcast Audio Mixer

Automatically balance your original voiceovers and background music with professional sidechain compression directly in your browser.

What is Auto-Ducking?

Auto-Ducker is a smart, free online audio processing tool that utilizes a technique called sidechain compression. When you mix a voice recording with a musical bed, the background music can often overpower the voice, making it hard to hear. This tool intelligently "listens" to your voice track. Whenever it detects you speaking, it instantly lowers (ducks) the volume of the background music. When you stop speaking, the music smoothly returns to its original volume. All of this happens instantly and securely within your web browser, with zero server uploads required.

How to mix your voice and music?

First, upload your main voice track in the left panel. Then, upload your royalty-free background music in the right panel. The tool will automatically sync them. You can adjust the "Voice Threshold" (how loud the voice needs to be to trigger the effect) and "Music Reduction" (how quiet the music should get). Use the "Preview Mix" button to listen to the result in real-time. Once the balance sounds perfect, click "Render & Download" to save your professionally mixed .wav file.

Who uses this tool?

This browser-based podcast voiceover mixer is a staple for podcasters, YouTube video creators, audiobook narrators, and anyone who needs to quickly mix their original spoken word audio with a royalty-free musical bed without spending hours manually automating volume levels in a complex editing program.

How to Use the Auto-Ducker in 3 Steps

Step 1

Upload Both Tracks

Upload your main voiceover track in the left panel, and your royalty-free background music in the right panel.

Step 2

Tweak Settings

Adjust the depth to decide how quiet the music gets, and set the release for how fast it comes back up.

Step 3

Export the Mix

Preview the automatic sidechain effect live, then click Render to download the perfectly mixed WAV file.

Auto-Ducker Tool Area

1. Voice Track (Main)

Upload speech / vocal file

Loaded:

2. Background Music

Upload background track

Loaded:

Ducking Settings

Pro Tip: Need more editing? After downloading, you can professionally master, apply 3-Band EQ, and convert your tracks for free using our Sound Optimizer & Audio Enhancer
Audio Tip: Because this tool processes 2-channel stereo audio, we highly recommend using headphones for the best performance.
Mobile Users: If playing without headphones, ensure your device's Silent/Mute switch is OFF to hear sound from the speakers.
Pro Tip: Need your file in .MP3 format? Export as WAV here, then use our fast converter.
WAV to MP3 Converter

Frequently Asked Questions

Is the Auto-Ducker Tool really free?
Yes. The Auto-Ducker is completely free to use, requires no signup, and has no daily limits. You can mix and process as many podcast episodes or voiceovers as you need.

Are my audio files safe and private?
Absolutely. All the sidechain compression and mixing is performed locally within your web browser using WebAudio API. Your private audio files are never uploaded to any external servers.

What is Sidechain Compression?
It is a studio technique where the volume of one track (the music) is controlled by the volume of another track (your voice). When you speak, the compressor automatically pushes the music down so your voice remains clear and easy to understand.

What do the Attack and Release sliders do?
Attack determines how quickly the music volume drops when you start speaking. A fast attack (e.g., 50ms) ensures the music ducks instantly. Release determines how long it takes for the music to return to full volume after you stop speaking. A longer release (e.g., 500ms) makes the transition sound smoother.

Do I need to install any software?
No. The Auto-Ducker works entirely online directly within your web browser. You don't need to learn complex automation curves in heavy software like Premiere, Audacity, or Pro Tools.

Can I change the format to MP3 after mixing?
Yes. The tool outputs a high-quality, lossless WAV file to preserve the clarity of your voice. Once downloaded, you can use our free WAV to MP3 Converter on this site to compress it for podcast distribution.