Reverse Audio

How to reverse audio

Three steps, in your browser.

1. 1

   Drop the file

   MP3, M4A from an iPhone, WAV, FLAC and other common formats up to 100 MB and 30 minutes. The page draws the waveform with the whole file selected.

2. 2

   Pick the part and the output

   Leave everything selected to reverse the whole file, or drag the handles (or type start and end times) to reverse one part. Choose reverse in place, the reversed part only, or forwards then backwards, and press Play reversed to hear it.

3. 3

   Save and download

   Press Reverse and save. The result is written as an MP3 at the bitrate you choose or as a 16-bit WAV, with a player to check it before you download.

Three ways to reverse

• Reverse in place

  The selected part plays backwards and the audio around it stays where it was. A 5-millisecond ramp at each join keeps the switch from clicking. With the whole file selected, this simply reverses the file.

• Reversed part only

  Saves just the selected part, backwards. Handy for a reversed cymbal, a single word or a short sound you want to drop into an edit.

• Forwards, then backwards

  The selected part as recorded, then the same part reversed, so the clip runs out and back. Both halves meet on the same sample, so the turn is smooth.

• What stays the same

  Only the order of the samples changes. Volume, sample rate and stereo channels are kept, and each channel is reversed on its own, so left stays left.

What people reverse audio for

• Hidden messages and backmasking

  Backmasking is a recording technique in which a message is recorded backward onto a track meant to be played forward. Reversing a song or a voice clip is the way to check what is really there.

• Reversed cymbals and swells

  A cymbal or piano note played backwards rises into the next beat instead of fading out. Reverse the hit on its own and place it just before the moment it should lead into.

• Sound design for video

  Reversed speech, footsteps or ambience sounds familiar and strange at once, which suits dream scenes, transitions and title sequences.

• Language games

  Record yourself saying a word, reverse it, and try to imitate the backwards version. Reverse your imitation and see how close it comes to the original.

What reversing does and does not change