# Reverse Audio

> To reverse audio online, load a file into the tool above or press Record your voice, then press Play reversed and Download WAV. The audio is flipped in your browser, so it's never uploaded. It's free with no account. Files can be up to 60 MB, about an hour of 128 kbps MP3, and recordings up to 60 seconds. The download is always a WAV, not an MP3.

URL: https://kenerateai.com/reverse-audio
Publisher: Kenerate AI (https://kenerateai.com)
Last updated: 4 November 2026

## Key facts
- Opens: MP3, WAV, M4A, OGG (what your browser decodes)
- File limit: 60 MB (about 1 hour of 128 kbps MP3)
- Recording: Up to 60 seconds from your microphone
- Download: 16-bit WAV, stereo or mono
- Speed and pitch: Unchanged, only the direction flips
- Privacy: Processed on your device
- Cost: Free, no account, no watermark
- Demo "Crate Digger" (Boom-bap, MiniMax Music 3.0): prompt: Classic boom-bap hip-hop beat, dusty kick and snare, chopped soul sample, deep bass, head-nod groove, 90 bpm
- Demo "Rio Afternoon" (Bossa nova, Ken Music 1.5): prompt: Bossa nova, nylon-string guitar, soft brushes, flute melody, warm and breezy, Rio beach afternoon, 124 bpm
- Demo "Hands Up" (EDM, MiniMax Music 3.0): prompt: Big-room EDM festival track, huge build-up, massive drop with punchy kick and lead synth, crowd energy, 128 bpm

## Steps
1. Add your audio — Choose an MP3, WAV, M4A or OGG up to 60 MB, or press Record your voice and allow the microphone.
2. Press Play reversed — The audio is already flipped. The waveform shows it running backwards.
3. Compare with the original — Play original plays it forwards, so you can check both.
4. Download the WAV — Download WAV saves the reversed version as a new file. Your original isn't changed.

## In depth

### How to reverse a song or a voice note
A song and a voice note work the same way here. For a song, load the file. For a voice note, either load the file your phone saved or record a new one with the button above the waveform.
If the file is long and you only want a few seconds, trim it first. A short clip is quicker to open, gives a smaller WAV and is easier to use in a video or a track.

### What reversed speech sounds like
Reversed speech doesn't sound like words. It has the same voice and the same rhythm of syllables, but sounds that normally start sharply, such as a “t” or a “k”, now fade in and stop suddenly. Vowels hold up better, which is why it can feel almost like a foreign language.
That's also why a reversed sentence isn't simply the words in the opposite order. Each sound inside each word is backwards too, so “hello” doesn't become “olleh” as you'd read it.

### What people use reversed audio for
The most common uses:
- Sound design — a reversed hit makes a rising “whoosh” into a scene change or a drop.
- Reverse cymbals — a crash played backwards swells up to a peak, so it can lead into the next section of a song.
- Reverse reverb — reverse a sound, add reverb in an audio editor, then reverse it again, so the echo arrives before the sound.
- The reverse singing challenge — copy a backwards phrase, record it and reverse it to see how close you got.
- Curiosity — checking what a song or a word really sounds like the other way round.

### Hidden messages in songs
Backmasking means recording a sound backwards onto a track that's meant to be played forwards. It's real as a studio technique: The Beatles popularised it, and Electric Light Orchestra's “Fire On High” contains a deliberate backwards message [1].
The claim that songs carry secret backwards messages that influence listeners is a different thing. As Wikipedia summarises the research, Vokey and Read found no effect from the meaning of backward messages on listeners' behaviour [1], and in a study of 40 people, listeners couldn't hear the alleged phrases unless they were prompted first [2]. Hearing words in reversed sound is usually pareidolia: the brain finding patterns in noise. This tool shows you what's on the recording, and it can't tell you what anyone meant by it.

### What happens to your file
When you choose a file, the browser reads it from your disk and decodes it into raw audio in memory, using the Web Audio API [3]. Recordings are captured the same way, with the browser's MediaRecorder [4]. The tool then reverses the samples of each channel. No part of the audio is sent anywhere, and closing the tab clears it.
Voice clean-up filters are switched off while recording, because they can cut out held notes and quiet sounds. That means background noise stays in, so a quiet room helps.

### How long big files take
We timed the tool on 4 November 2026 in Edge on one Windows desktop, using generated test tones. Your times will differ, and we haven't measured phones or other browsers.
- One-hour MP3, 57.6 MB at 128 kbps — opened and reversed in 8.9 seconds. Exporting took 1.8 seconds and made a 691.2 MB WAV.
- 5 minute 40 second WAV, 60 MB — opened in 0.8 seconds and exported in 0.2 seconds.
- A full 60-second recording — stopped on its own at the limit and came to an 11.5 MB WAV.
- Anything over 60 MB — refused with a message, before it's read.

### Why the download is a WAV
Browsers can decode MP3 but don't come with a way to write one, so an MP3 export would need an extra encoder inside the page. This tool doesn't have one. WAV is plain uncompressed audio, which also means the reversed sound isn't compressed a second time.
The catch is size: about 10.6 MB per minute for stereo at 44.1 kHz, and about 11.5 MB at 48 kHz. The tool saves at your browser's audio rate and shows the size before you download.

References:
[1] Wikipedia — Backmasking: https://en.wikipedia.org/wiki/Backmasking
[2] Wikipedia — Reverse speech: https://en.wikipedia.org/wiki/Reverse_speech
[3] MDN — BaseAudioContext.decodeAudioData(): https://developer.mozilla.org/en-US/docs/Web/API/BaseAudioContext/decodeAudioData
[4] MDN — MediaRecorder: https://developer.mozilla.org/en-US/docs/Web/API/MediaRecorder

## FAQ
Q: How do I reverse an audio file for free?
A: Load it into the tool at the top of this page, press Play reversed to hear it, then press Download WAV. It's free, with no account and no watermark.

Q: How do I reverse my voice?
A: Press Record your voice, allow the microphone, speak, then press Stop recording. The recording is flipped as soon as it stops, so Play reversed plays your voice backwards. Recordings can run up to 60 seconds and stop on their own at the limit.

Q: Is my audio uploaded?
A: No. Your browser decodes the file or recording and flips it on your device, so the audio never reaches our servers.

Q: Does reversing audio change the speed or pitch?
A: No. The samples play in the opposite order at the same rate, so the length stays the same and nothing is sped up or slowed down. A melody does sound different, because its notes arrive in the opposite order and each one swells instead of striking. To change tempo, use the BPM changer.

Q: Can I download the reversed audio as an MP3?
A: No, not here. The tool only exports WAV, because browsers don't include an MP3 encoder and this tool doesn't add one. If you need an MP3, convert the WAV in a desktop app such as Audacity.

Q: Can I reverse only part of a song?
A: Not in this tool, which flips the whole file. Cut the part you want with the free audio trimmer, then load that clip here.

Q: How does the reverse singing challenge work?
A: Record a short phrase and press Play reversed. Copy the backwards sound as closely as you can, record that attempt, and reverse it. The closer your copy, the more it sounds like the original phrase. A new recording replaces the last one, so download first if you want to keep it.

Q: Are there really hidden messages in songs played backwards?
A: A few artists have put deliberate backwards parts in their music. The famous claims of secret messages are another matter: studies summarised on Wikipedia found people rarely hear the alleged phrases unless they're told what to listen for. Your brain is good at finding words in noise.

Q: Why won't the Record button work?
A: Your browser has to be allowed to use the microphone. If you blocked it, change the permission for this site in your browser's settings and try again. You can always load a recording you already have as a file instead.

Q: How big a file can I reverse?
A: Up to 60 MB. On a Windows desktop in Edge, a one-hour 128 kbps MP3 of 57.6 MB opened and reversed in about 9 seconds. We haven't measured phones, which have less memory, so long files may fail there. If one does, try a shorter file.

## Related pages
- Sound test: https://kenerateai.com/sound-test
- Audio trimmer: https://kenerateai.com/audio-trimmer
- Extract audio from video: https://kenerateai.com/extract-audio-from-video
- BPM changer: https://kenerateai.com/bpm-changer
- Slowed + reverb maker: https://kenerateai.com/slowed-reverb-maker
- AI music generator: https://kenerateai.com/ai-music-generator

## Sources
- MDN — Web Audio API: https://developer.mozilla.org/en-US/docs/Web/API/Web_Audio_API