Audio and video merge

Combine separate media tracks locally

Choose one video file and one audio file. GrabFlow copies compatible tracks into a new MP4 without uploading your media.

Choose two files

Local track merger

Local processing

Select a video file that contains the picture track.

Choose videoOne file · Up to 500 MB

Select the separate audio file you want to combine.

Choose audioOne file · Up to 500 MB

MP4 output using stream copy

No re-encoding is performed. The selected tracks must already be compatible with an MP4 container.

This first version copies existing tracks without re-encoding. Common H.264 video and AAC audio are the most reliable combination.

Both input files are processed in browser memory and are not uploaded to GrabFlow servers.

Browser processing needs additional memory for both inputs and the output. Start with smaller files and keep this tab open.