Add or Replace Audio in Video

What is the Add or Replace Audio in Video Tool?

An Add or Replace Audio in Video tool is a free online utility that lets you add music, voiceovers, or sound effects to your videos by mixing them with the original sound, or completely replace the existing audio track. If your video has no sound initially, the new audio is simply added. The final video always matches the length of your original video.

This tool uses FFmpeg.wasm to process everything directly in your browser. Your files never leave your device, ensuring complete privacy and security. It supports common video formats like MP4, WebM, and MOV, and common audio formats like MP3, WAV, and AAC.

How to Use This Tool

1. Load the engine: Wait for the FFmpeg processing engine to load in your browser.
2. Upload your video: Click the upload area or drag and drop your video file (MP4, WebM, MOV, etc.).
3. Upload your audio: Upload the audio file (MP3, WAV, AAC, etc.) you want to add or replace.
4. Configure audio settings: Choose "Add to Video (Mix)" to combine with original sound, or "Replace Video's Audio" to use only the new audio. Adjust volume using the dB slider. Choose whether to play the audio once or loop it.
5. Process: Click the "Process Video" button and wait for the conversion to complete.
6. Preview and download: Preview the result and click "Download Processed Video" to save your file.

Key Features

• Add or Replace Audio: Choose to mix new audio with the original sound or replace it entirely.
• Mix with Original Sound: When adding, the original audio plays at its normal volume while the new track is mixed in.
• Replace Original Sound: When replacing, the original audio track is completely removed and replaced.
• Matches Video Length: Output video duration is identical to the original. Audio is trimmed or looped as needed.
• Loop or Play Once: If the new audio is shorter, choose to loop it or play it just once.
• Volume Control: Adjust the loudness of the new audio track using a decibel (dB) scale.
• Client-Side Processing: All processing happens in your browser using FFmpeg.wasm. No uploads required.
• Progress Tracking: See real-time progress of the audio processing.

Common Use Cases

• Add background music: Add royalty-free music to your video content for social media or presentations.
• Replace audio track: Swap out a video's original audio with a better quality recording or different language version.
• Voiceover narration: Add narrated voiceovers to explainer videos, tutorials, or presentations.
• Create video mashups: Combine video from one source with audio from another for creative projects.
• Fix audio issues: Replace poor quality or unwanted audio with a clean recording.

If you are editing videos, you may also find our Adjust Video Speed tool useful for creating slow-motion or time-lapse effects. The Flip Video tool handles horizontal and vertical mirroring, and the Add Watermark to Video tool lets you overlay logos or text to protect your content.