Merge video and audio in your browser
Combine a video-only file and an audio track into one MP4 without uploading either file. Puxli reads and writes the media on your device, which keeps private or large source files out of a remote conversion queue.
Merge video + audioLocal merging remuxes compatible tracks without intentionally re-encoding them. The output quality therefore follows the selected source files.
A local media merger built for privacy
Files stay on your device
The selected video and audio are processed by your browser and are not sent to Puxli.
No quality inflation
Compatible streams are placed into one MP4 without claiming to create resolution or detail that is not present.
Useful for separate tracks
Combine high-resolution video-only streams with their matching audio track after downloading both.
How to combine video and audio
- 01
Select the video
Choose a compatible video-only file from your device.
- 02
Select the audio
Choose the matching audio track and pick where the final MP4 should be saved.
- 03
Merge locally
Keep the tab open while your browser writes the finished file directly to the selected location.
Local merger questions
Are my files uploaded?
No. The merger does not use fetch or an upload request. Media stays inside your browser and local file system.
Does merging reduce quality?
Puxli remuxes compatible encoded tracks instead of intentionally transcoding them, so it does not add a normal encode-quality loss.
Which browser works best?
Desktop Chrome and Edge provide the file-writing features needed for large outputs. Other browsers may offer a memory-limited fallback.
Why are video and audio separate?
High-resolution services often deliver adaptive video and audio as separate streams. Combining them creates a normal file with both tracks.