What it does
Reverses your audio file, last sample becomes first, first becomes last. The result is the entire track played backward. Output format matches the input (MP3 stays MP3, WAV stays WAV, etc.).
Server-side processing uses FFmpeg’s areverse filter, which buffers the entire file into memory and writes samples in reverse order. The audio quality is preserved up to whatever the format allows.
Why people reverse audio
Three real cases:
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Music production: reverse cymbals, reverbs, vocal lines. A common production technique, record forward, reverse, layer. Beatles famously used reversed audio on Revolver and several later records.
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Sound design for video / film: reversed sounds feel uncanny and unnatural. Useful for sci-fi, horror, or surreal scenes. A reversed gunshot makes a great backwards-suction sound.
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Hidden message tests / curiosity: people occasionally want to reverse a song to check for “backwards messages.” Most are imagined; some are deliberate (Pink Floyd, ELO). Reverse the audio to listen for yourself.
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Pranks / memes: reversed speech sounds bizarre and is endlessly meme-able.
What gets reversed
The audio waveform itself, sample by sample. Metadata (artist, title, album art, ID3 tags) is preserved when possible, those don’t get “reversed,” they just stay attached.
For multi-channel audio (stereo, 5.1), each channel is reversed independently. Stereo recordings sound the same in reverse: left stays left, right stays right.
File size limits
This tool processes the entire audio file in memory. Files up to about 100MB process quickly (under a minute). Very long audio (multi-hour podcasts) may hit the timeout, use the audio trimmer first to extract a shorter section.
Frequently asked questions
Will the reversed file have the same length as the original? Yes. Reversing changes the order of samples but not the count. A 3-minute song becomes a 3-minute reversed song.
Does this work on MP3 without re-encoding? No. MP3 frames have to be decoded to PCM, reversed, and re-encoded. There’s a tiny amount of generation loss from re-encoding. For lossless reversal, use WAV or FLAC input → WAV output.
Why does my reversed speech sound different from my voice played backward? Acoustic recordings include reverb tails, the sound of the room, which extend after each spoken word. Reversed, those tails come before each word, producing a “swelling into” effect that doesn’t exist in dry voice samples. Studio-recorded dry vocals reverse much more cleanly.
Can I reverse just part of the audio? This tool reverses the whole file. To reverse a section, trim first with the audio trimmer, then reverse the trimmed file.