Add or change video sound track

Online tool for adding audio to video files and GIFs

This free online audio tool lets you combine any video or animated image with a custom audio track, producing a single output file with both picture and sound. It works entirely in the browser — no software to install, no watermarks added, and no account required.

How it works

Upload a video file (MP4, WebM, AVI, MOV, MKV) or an animated image (GIF, APNG, WebP) using the form above. Then upload an audio file to attach to it. The tool merges the two tracks server-side and returns a downloadable video with your chosen audio. If you upload an animated GIF, it is automatically converted to a video format first, because the GIF specification does not support embedded audio.

Supported formats

Video input: MP4, WebM, AVI, MOV, MKV, and most other common video containers.
Image input: Animated GIF, APNG, and WebP files are accepted and converted to video.
Audio input: MP3, WAV, M4A (AAC), and OGG/Vorbis files up to 100 MB.

Audio mixing options

You have full control over how the audio is combined with the video:

• Replace — removes the original audio and uses only the uploaded track.
• Mix — keeps the original audio and layers the new track on top of it.
• Remove — strips all audio from the video entirely.

Additional settings let you adjust the volume (0–200%), set an exact start time for when the new audio begins, and choose how to handle length mismatches between the video and audio (trim, loop audio, loop video, or extend with silence). Fade-in and fade-out controls (up to 10 seconds each) are available for smooth audio transitions.

Related audio tools

If you want to remove sound from a video entirely, use the Mute Video tool. To increase or decrease the volume of the existing audio track without adding a new one, try the Volume Booster. You can also extract audio from video as an MP3 file.

Frequently asked questions

Can I add music to a GIF?

Yes. Upload your animated GIF and an audio file (MP3, WAV, M4A, or OGG). The tool converts the GIF into an MP4 video with your audio track attached. The original GIF format does not support audio, so the output is always a video file.

What is the maximum file size?

The video file can be up to 200 MB and the audio file up to 100 MB. If your files are larger, try compressing them first or trimming them to a shorter duration.

Can I mix the new audio with the original sound?

Yes. Set the "Original audio" option to "Keep original audio (mix)" and both tracks will be merged together. You can adjust the volume of the new track independently using the volume slider.

What happens if the audio is longer than the video?

By default the longer track is trimmed to match the shorter one. You can also choose to loop the video to match the audio length, loop the audio to match the video, or extend the shorter track with silence.