Does this tool upload my files to a server?

No—everything happens in your browser. Your video and music never leave your device. Only your computer or phone processes the files.

Will my video lose quality?

No, the video stream is copied directly. Only audio is re-encoded, so the picture stays identical to your original.

What audio formats can I use for music?

You can use MP3, WAV, M4A, FLAC, OGG, or AAC files. Most music you download or record yourself will work.

Can I use commercial songs as background music?

Only if you own the rights or have a license. For public uploads, use royalty-free tracks or your own recordings to avoid copyright issues.

How does automatic ducking work?

Ducking detects when someone is speaking in the original audio and lowers the music volume during those moments. It helps speech stay clear over background music.

Can I keep both the original audio and my music?

Yes—use the Mix Under or Duck mode. The original audio stays, and your music is blended beneath or ducked around speech.

Is there a file size or length limit?

Processing happens in your browser, so files over 2–3 GB or longer than about 2 hours may fail on some devices. For most clips, it works fine.

What format is the output audio?

The audio is always encoded as AAC at 192 kbps, which is widely supported and a good quality for video sharing.

Can I adjust where the music starts or fades in/out?

Not directly—music always starts with the video. For fades or advanced timing, use a desktop editor or prepare your audio in Audacity first.

100% free · runs in your browser · no upload · no signup

Add your own music or audio track to a video

Drop a file here

Click to browse, or paste a file from the clipboard.

Choose file

You can add music or any audio track to your video by mixing it under, ducking it around speech, or replacing the original sound entirely. Videozify does this in your browser, keeping the video quality identical and only re-encoding the audio to AAC at 192 kbps. Common uses are background music for vlogs, intros, slideshows, or simply swapping out a noisy original track. Choose your video and music, pick a mode, set the music volume, and download the result—no file uploads.

How to add music to a video

Drop your video file and your music or audio file onto the boxes above.
Choose how you want the music added: mix under, duck, or replace.
Set the music volume (15%, 35%, 60%, or 100%) and if you want the music to loop.
Press Add music to video and wait a few seconds.
Download the new video with your audio mixed in.

How adding music to video works

Videozify combines your video and audio files locally in your browser using FFmpeg compiled to WebAssembly. Your files are never uploaded—everything happens on your device. The video stream is copied directly, so there’s no loss of picture quality or extra waiting for re-encoding. Only the audio track is processed, then encoded to AAC at 192 kbps, which is a solid balance between quality and file size for most uses.

You can choose between three modes: mixing music under the original sound, ducking music automatically when speech is detected, or replacing the original audio entirely. Music can be set to loop if it’s shorter than the video, or just play once and stop. The output always matches your video’s duration.

This tool is designed for your own videos and audio. For best results, use music you own the rights to—such as royalty-free tracks, your own recordings, or licensed music. Using commercial music without permission can lead to copyright issues if you post the video online.

There are a few limits. Because processing happens in your browser, very large files (over 2–3 GB or longer than about 2 hours) may run into memory issues, especially on phones. The audio is always re-encoded to AAC. If you need to keep the exact original audio format, use a dedicated desktop editor. But for most social posts, presentations, and sharing, this tool is much faster and simpler.

Everything runs locally in your browser. For advanced audio timing or fades, try Audacity or a full video editor.

At a glance

Property	Videozify
Video quality	Original (no re-encode)
Audio output	AAC, 192 kbps
Mixing modes	Mix under, ducking, replace
Music file types	MP3, WAV, M4A, AAC, FLAC, OGG
Max file size	~2–3 GB (browser limit)
Processing	Local (no upload)

Add music or an audio track to your video by mixing it under, ducking it around speech, or replacing the existing audio. The video stream is copied directly for zero quality loss.

Settings explained

Mode: Mix under, duck, or replace. 'Mix under' blends your music quietly beneath the original sound—good for vlogs and slideshows where you want both the original and music. 'Duck' uses automatic sidechain compression: the music drops in volume when speech is present, making voices clear while keeping background music audible. 'Replace' removes the original audio and uses only your music—ideal for silent footage, presentations, or when the original track is unusable.

Music volume: Choose from 15%, 35%, 60%, or 100%. 15% is background level—barely noticeable under speech. 35% is typical for gentle background music. 60% is prominent but not overpowering. 100% uses the original music level—best if you are replacing the audio entirely. If the result is too loud or too soft, try another setting.

Loop music: If your music is shorter than the video, enable looping to repeat the track until the video ends. Otherwise, the music will play once and then stop, leaving the rest of the video silent. The output is always cut to match the video’s length, so you don’t have to trim anything manually.

Tips and alternatives for adding music to video

Pick music you have rights to. Royalty-free libraries, your own recordings, or tracks with a clear license are best. Uploading videos with unlicensed commercial music can lead to takedowns or muted sound on social platforms.

For simple tasks, Windows Clipchamp and macOS iMovie also let you add music to videos. iOS Photos and Android gallery apps often have a basic music overlay, but with fewer controls. These built-in options are fine for quick edits but may re-encode and lower video quality, and sometimes limit export resolution or format.

If you want fades, precise timing, or to edit the music file itself, desktop tools like Audacity (for audio) or CapCut (for video) let you prepare your track first. Mix and trim your audio, then use Videozify to combine it with your video without touching the video quality.

VLC can play a video with a different audio track but can’t save the result as a new file. For permanent changes, use a tool that combines the tracks and exports a new video. Videozify does this quickly and losslessly for the video stream.

Frequently asked questions

Does this tool upload my files to a server?: No—everything happens in your browser. Your video and music never leave your device. Only your computer or phone processes the files.
Will my video lose quality?: No, the video stream is copied directly. Only audio is re-encoded, so the picture stays identical to your original.
What audio formats can I use for music?: You can use MP3, WAV, M4A, FLAC, OGG, or AAC files. Most music you download or record yourself will work.
Can I use commercial songs as background music?: Only if you own the rights or have a license. For public uploads, use royalty-free tracks or your own recordings to avoid copyright issues.
How does automatic ducking work?: Ducking detects when someone is speaking in the original audio and lowers the music volume during those moments. It helps speech stay clear over background music.
Can I keep both the original audio and my music?: Yes—use the Mix Under or Duck mode. The original audio stays, and your music is blended beneath or ducked around speech.
What happens if my music is shorter than the video?: Enable 'Loop music' to repeat your track until the video ends. Otherwise, the music will play once and then stop, leaving silence.
Is there a file size or length limit?: Processing happens in your browser, so files over 2–3 GB or longer than about 2 hours may fail on some devices. For most clips, it works fine.
What format is the output audio?: The audio is always encoded as AAC at 192 kbps, which is widely supported and a good quality for video sharing.
Can I adjust where the music starts or fades in/out?: Not directly—music always starts with the video. For fades or advanced timing, use a desktop editor or prepare your audio in Audacity first.