Reverse Audio
Create a file that plays from the end to the beginning — handy for sound design and for testing whether a lyric really does say something backwards.
The conversion engine (about 32 MB) loads once on your first run and starts instantly from cache afterwards.
What it is good for
Reversal is a classic sound-design trick: a reversed cymbal or piano note makes the sucking swell used all over film transitions. It is also the tool for checking backmasking claims. Running the output through this page again restores the original direction.
How to use it
Pick a file and processing starts; the only settings are output format and bitrate. Reversal holds the whole file in memory, so it is most comfortable up to about five minutes. Split longer recordings first.
Things to watch
Reversing swaps attack and decay, so the character of the sound changes a lot, and any existing fades end up on the wrong ends. If you want fades, add them after reversing on the fade page.
Frequently asked questions
Can I undo the reversal?
Yes — run the reversed file through the tool again. Use WAV for the round trip so you are not re-encoding twice.
Can I reverse the audio in a video?
You can load a video and get reversed audio out of it, but no video is produced.
How long does it take?
A few seconds for a file of a few minutes. It uses more memory than the other tools because the whole file must be held at once.