Replace Audio in Video Online Free
Add new music or voiceover to any video instantly
No signup • No watermark • 100% Private • Completely Free
See the Result
Processing time: Fast (no video re-encoding)
Step 1: Upload Video
Upload Your Video
Drag and drop or click to select
Supports MP4, MOV, AVI, WebM
Step 2: Upload New Audio
Upload Audio File
Drag and drop or click to select
Supports MP3, WAV, AAC, M4A, OGG
ℹ️How It Works
- •Upload your video and the new audio file you want to use
- •The tool removes the original audio and adds your new audio track
- •Video is not re-encoded, so quality remains perfect
- •Audio is automatically trimmed to match video length
- •All processing happens in your browser — files never leave your device
Why Use Our Free Audio Replacer?
100% Private & Secure
Your files never leave your device. All processing happens directly in your browser using WebAssembly.
Fast Processing
Replace audio in seconds. No waiting for server uploads or downloads — everything happens locally.
Completely Free
No hidden costs, no subscriptions, no credit card. Use unlimited times forever.
No Signup Required
Open the tool and start immediately. No account, no email, no waiting.
How to Replace Audio in Video
Upload Your Video
Drag and drop or click to select any MP4, MOV, AVI, or WebM file.
Upload New Audio
Choose your MP3, WAV, AAC, M4A, or OGG audio file.
Click Replace Audio
One button click starts the process — it only takes seconds.
Download Result
Your video with new audio is ready to download as MP4 immediately.
Frequently Asked Questions
Is this audio replacement tool really free?
Yes, completely free. No hidden fees, no subscriptions, no credit card required.
Do I need to create an account?
No. Start immediately without signup or email verification.
Are my files uploaded to your servers?
No. All processing happens in your browser. Files never leave your device.
What video and audio formats are supported?
We support MP4, MOV, AVI, WebM for video and MP3, WAV, AAC, M4A, OGG for audio. Output is always MP4.
Will video quality change after replacing audio?
No. This tool uses stream copy for video, which means the video is not re-encoded. Quality remains 100% identical to the original.
What happens if my audio is shorter than the video?
The video will continue playing after the audio ends, with silence for the remaining duration.
What happens if my audio is longer than the video?
The audio is automatically trimmed to match the video length. Only the portion that fits will be used.
Can I adjust the audio volume?
The current version uses the original audio volume. You can adjust volume in your audio file before uploading, or use an audio editor.
💡Pro Tip: When to Replace Audio in Videos
- •Replace copyrighted music with royalty-free tracks before uploading to YouTube
- •Add professional voiceovers to screen recordings and tutorials
- •Fix audio issues without re-exporting the entire video
- •Create multiple versions of the same video with different background music
- •Video quality stays perfect because only audio is replaced — no re-encoding
- •Audio is automatically trimmed to match video length for perfect sync
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