Audio Reverser

Reverse audio playback direction for creative sound effects.

Tested tool guide Tested browser tools Checked August 15, 2026

What Audio Reverser does, with a checked example

This tool takes an audio file, decodes it into its raw samples, and writes those samples out in reverse order so the clip plays from end to start. Duration, sample rate, and pitch are untouched - only the direction of playback changes. The thing people get wrong most often is expecting reversed speech to reveal a hidden intelligible message; in practice it almost always comes out as an unintelligible warble, not backward-masked words. A fade-in at the start of the original also becomes a fade-out at the end of the reversed file, since the whole envelope mirrors around the midpoint.

Worked example

A concrete input and expected output from the current implementation.

Input

a 2.0-second, 44.1kHz stereo WAV file of a hi-hat swell that fades in

Expected output

a 2.0-second, 44.1kHz stereo WAV file with the same sample count, sample rate, and channel count, where the swell now fades out - the sound plays end-to-start

Reversal only reorders the sample sequence per channel; it cannot change duration, sample rate, or channel count, so those stay identical while the fade direction flips. The decoded-and-re-encoded WAV is not guaranteed to keep the exact chunk layout or metadata of the original file, only the audio properties listed above.

How the result is produced

Per-channel sample reversal

The file is decoded into raw PCM samples, one array per channel. Each channel's samples are written out in reverse index order - last sample first, first sample last - while channels stay aligned to each other, so stereo imaging and left/right sync are preserved in the reversed result.

Envelope mirroring

Because reversal flips the whole timeline, any volume shape in the original mirrors around the clip's center: a fade-in becomes a fade-out, a decaying cymbal crash becomes a swelling one, and trailing silence moves to the front. No level or timing values are recalculated - only their position in time changes.

Good uses

musicians building a classic backward guitar swell or reversed cymbal effect
sound designers making a reverse-whoosh riser to lead into a transition or hit
editors flipping a short recorded phrase into unintelligible backward speech for a sound gag

Limits and checks

Reversal does not alter pitch, tempo, sample rate, or file length - only playback direction - so it will not fix or change how fast or high something sounds.
Reversing a file twice does not exactly restore the original once any lossy re-encoding (such as MP3) has been applied in between, because each encoding pass introduces its own small artifacts.
Reversed speech typically sounds like an unintelligible warble rather than backward-masked hidden words; reversing it a second time (with no lossy re-encoding in between) restores the original, intelligible speech, since sample reversal is its own inverse.

Common questions

Will this change the pitch or speed of my audio?

No. Reversing only flips the order samples play in - pitch and tempo stay exactly as they were in the original file. If you want a pitch shift or a speed change, that needs a separate pitch or tempo tool; this one only handles direction.

Can I reverse just one section of a longer file instead of the whole thing?

This tool reverses the entire file you load, not a selected range. To reverse only part of a track, trim or cut out that section with a separate audio-trimming tool first, then run the trimmed piece through this reverser.

References and verification

The example and behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.