Audio Reverser
Choose a song, voice memo or sound effect and hear it backwards instantly. Compare the original and reversed waveforms, play either one, and download the reversed audio as a WAV file. Everything happens in your browser.
Original
0:00 / 0:00Reversed
0:00 / 0:00How to use the Audio Reverser
- Choose an audio file by dropping it on the box or clicking to browse.
- Listen: press Play reversed to hear it backwards, or Play original to compare. Click a waveform to start from that point.
- Adjust the options if you like: loop the playback, add a short fade to avoid clicks, or mix down to mono.
- Press Download reversed WAV to save the file as name-reversed.wav.
How reversing audio works
Digital audio is a list of numbers called samples: the position of the speaker cone measured thousands of times per second (44,100 times per second for CD audio). Reversing a recording simply means reading that list from the end to the start. If the original samples are x[0], x[1], … x[N − 1], the reversed signal is y[n] = x[N − 1 − n]. Each stereo channel is reversed separately, so the left and right sides stay where they were.
Because nothing is resampled or stretched, the reversed audio has exactly the same length, pitch and loudness as the original. What changes is the envelope: a piano note that normally starts with a sharp attack and fades away now swells up slowly and stops abruptly, which is the familiar “reverse” sound used in music production.
WAV file size at a glance
| Audio | Sample rate | Channels | Size per minute (16-bit WAV) |
|---|---|---|---|
| Voice memo | 16,000 Hz | Mono | 1.9 MB |
| Podcast | 44,100 Hz | Mono | 5.3 MB |
| CD-quality music | 44,100 Hz | Stereo | 10.6 MB |
| Video soundtrack | 48,000 Hz | Stereo | 11.5 MB |
The size is sample rate × channels × 2 bytes × 60 seconds, plus a 44-byte header. Mixing a stereo file down to mono halves the size.
Creative uses for reversed audio
- Reverse cymbals and swells: reverse a crash cymbal or a reverb tail and place it just before a downbeat to build tension.
- Reverse vocals: sing or speak a phrase, reverse it, learn to imitate the reversed sound, record that and reverse it again for an eerie “forwards-backwards” effect.
- Sound design: footsteps, explosions and doors played backwards make unusual sci-fi and horror effects.
- Palindrome games: check whether a spoken word really sounds the same backwards.
Frequently asked questions
How do I play a song backwards?
Open the song file here and press Play reversed. The tool decodes the audio, flips the order of every sample on each channel and plays the result, so the last sound you hear is the first sound of the original.
What format is the reversed file?
A 16-bit PCM WAV file with the same sample rate and number of channels as the decoded audio. WAV plays in every media player and audio editor. Use an MP3 converter afterwards if you need a smaller file.
Why is the downloaded WAV bigger than my MP3?
MP3 is compressed, while WAV stores every sample uncompressed. One minute of CD-quality stereo WAV is about 10 MB, roughly ten times a typical MP3.
What is backmasking?
Backmasking is a recording technique where sounds or words are recorded backwards onto a track so that they are only understandable when the track is played in reverse. Musicians have used it for effects since the 1960s, and you can check claimed backmasked messages with this tool.
Why do I hear a click at the start or end?
If the audio does not start or end at silence, the jump from silence to sound can make a click. Turn on the 10 ms fade option to smooth both edges.
Is my audio uploaded?
No. The file is decoded and reversed entirely in your browser with the Web Audio API and never leaves your device.