Reverse Audio

What this tool does

Reverse Audio flips the order of the samples in an MP3, WAV, M4A or OGG file so it plays from end to start. Reverse only a dragged selection while the rest stays normal, or append a reversed copy for a seamless palindrome loop, then download the result as WAV.

Reversed sound has a long history in music, from tape loops played backwards in 1960s studios to the reverse cymbal swells used in modern pop. It is also a popular party trick: record yourself saying a phrase, reverse it, try to imitate the backwards version, then reverse that recording to hear how close you got.

This tool decodes your file with the Web Audio API and reverses the array of samples in every channel, which is mathematically exact: no pitch shifting or time stretching is involved, so the backwards version has the same length and tonal balance as the original. In selection mode it adds tiny 5 ms fades where the reversed part meets the untouched audio so the joins do not click. The result is written as WAV on your device.

How to use Reverse Audio

1. Drop an audio file, or a video whose sound you want, onto the upload area.
2. Choose a Mode: Whole file, Selection only, or Forward + backward.
3. For Selection only, drag across the waveform to mark the part to reverse; Select all resets it.
4. Click Play original and Play reversed to compare.
5. Choose a WAV bit depth and click Download WAV.

Tips for better results

• Reverse a single word or cymbal hit with Selection only to create a classic “swell” leading into the next beat.
• Forward + backward makes a loop whose end flows straight into its start, handy for ambient textures.
• Record a phrase with the Voice Recorder, reverse it here and play the backwards speech game.
• Trim silence from the end first, otherwise the reversed file begins with that silence.

Common use cases

• Creating reverse cymbals, reverse reverb swells and other sound-design effects.
• Playing the reverse-speech challenge with friends.
• Checking a recording for so-called backmasked messages in songs.
• Making seamless palindrome loops for games, videos or installations.

Common mistakes to avoid

• Expecting reversed speech to sound like the words said backwards; individual sounds such as plosives also play in reverse, so it sounds like an unfamiliar language.
• Forgetting that the output is uncompressed WAV and therefore much larger than the MP3 you started with.
• Selecting a range shorter than 10 ms in selection mode, which leaves the audio unchanged.