How to turn mono into stereo
1. Drop one audio file you already have. Video and pictures are refused here. 2. Press “Make stereo” and play the download in headphones. 3. The left and the right should match. Keep the original until a word still lands where you expect.
GustKit runs FFmpeg pan in this tab and re-encodes the file. The first channel is copied to both outputs. WAV stays WAV and MP3 stays MP3. A file that already has two different channels keeps only the first one, duplicated. Stereo to mono is the page that mixes both ears into one.
Mono to stereo is not a louder file
Change volume raises or lowers the whole recording and does not add a channel. Normalize audio sets a loudness target. This page only makes the file two channels wide. The length stays about the same.
The audio stays in this tab
The first visit downloads FFmpeg. Later visits reuse the browser cache. A file longer than the limit on the page is refused, because the whole file is re-encoded here. GustKit does not fetch audio from a link.
How to hear both ears before you replace the original
1. Play the download in headphones. A voice that was only in one place should now be in both ears. 2. Check the file info. It should say two channels, and the type should match the original. 3. Keep the original until the words still start where you expect.
Stereo to mono mixes two channels into one. This page copies the first channel into both. The length stays about the same. Nothing is uploaded.