Reverse Audio
Drop in a file, reverse all of it or only a part, listen, and export a WAV. It runs in your browser, handles files up to 150 MB and 15 minutes, and nothing is sent anywhere.
Use audio you made or have permission to use. Nothing is sent anywhere, so we never hear or keep it.
Reversed. Melodious can turn the finished track into a music video — See the music video maker
Six worked examples
The first three cases use ten numbers standing in for ten samples, so you can read the reversal directly. The last three run the tool's size arithmetic on a three-minute stereo track at 44,100 Hz.
The whole file, ten samples
- In: 1 2 3 4 5 6 7 8 9 10
- Out: 10 9 8 7 6 5 4 3 2 1
- Length: 10 samples, unchanged
Only samples 3 to 7 of the ten (0.3 s to 0.7 s)
- In: 1 2 3 4 5 6 7 8 9 10
- Out: 1 2 3 7 6 5 4 8 9 10
- Length: 10 samples, unchanged
Reversing twice gives the file back
- Once: 10 9 8 7 6 5 4 3 2 1
- Twice: 1 2 3 4 5 6 7 8 9 10
A three-minute stereo track, the last 10 seconds only
- Reversed: 170 s to 180 s
- Output: 3:00.000, 30.3 MB
A three-minute stereo track, all of it
- Reversed: the whole file
- Output: 3:00.000, 30.3 MB
A 15-minute stereo track is refused, not attempted
- Refused: That WAV would be 151.4 MB. The limit is 100.0 MB, because the file is built in your browser's memory. Choose a shorter part.
A sample is one measurement of the sound wave. Reversing a file reads those measurements back to front. Nothing is added or lost, which is why the length never changes.
How to reverse an audio file
Drop an audio file onto the box, or choose one. The page decodes it and draws its waveform. The default is to reverse the whole file, which is one click away from finished: press Play the result to hear it, then press the export button to save it.
To reverse only a section, switch to Only a part of it and set a start and an end. The highlighted part of the waveform is the part that will flip. Type the times for an exact edit, or move the sliders; the arrow keys nudge by a hundredth of a second. The readout gives the length and size of the file before you export.
What reversing does to a sound
Every sound has a shape in time. A struck drum begins with a sharp attack and dies away; a plucked string does the same. Reverse it and the shape turns inside out: the sound starts quietly, swells and ends on the sharp edge. That is why a reversed cymbal is used to lead into a downbeat, and why a reversed reverb tail seems to be pulled toward the note it belongs to.
Nothing else changes. Pitch stays where it was, because the same samples are being played at the same rate, only in the opposite order. A reversed vocal keeps its tone and loses its meaning, which is its appeal as a texture and the reason reversed speech so often seems to say something in a language you almost know.
Reversing a part, and joining it to the rest
The reversed region sits in the same place as the original, between the same two times, so the file stays as long as before and everything outside the region is byte for byte what you put in. The one thing to listen for is the boundary. A wave that is at a high level at the end of a normal section may meet a quiet reversed section, and the step between them can click.
If you hear a click, move the start or end by a few milliseconds to a quieter moment, or take the section into the audio cutter, add a short fade there and join the pieces again. Reversing a whole file has no boundary to worry about, which is the simplest case.
Limits, stated up front
The tool opens files up to 150 MB and 15 minutes, and refuses to write a WAV over 100 MB. The reason is memory: your browser decodes the whole file into floating-point samples, which takes many times the size of an MP3, and the reversed copy is built in memory before it is saved. Past a limit the tool says what the size would have been and what would fit.
It handles mono and stereo, keeps the first two channels of anything larger, and writes a 16-bit WAV at the rate your browser decoded the file at. It does not change pitch, speed or volume. Phones have less memory than computers, so keep files short there, and note that browsers differ in which formats they can open.
What to do with a reversed sound
A reversed hit usually needs trimming to start on its swell, and the audio cutter does that, with a fade if you want one. To repeat a reversed phrase as a bed, the audio loop maker repeats a region, and the audio joiner places it before or after the forward version. If the effect comes out quiet, the volume booster sets the level.
To see the sound as a picture, the audio visualizer turns a track into a moving visual. The BPM finder reads the tempo if you want the effect to land on a beat.
From a reversed sound to a finished video
A reversed transition or intro is a small part of a larger piece. For the wider route, the guide to making a music video for your song covers it end to end.
When the finished track should have scenes, a character and a story, the AI music video generator storyboards it and renders it to your audio. It is paid, from $19/month, and you see the cost before anything renders. The WAV you make here stays on your device unless you upload it yourself.
Frequently asked questions
How do I play a song backwards online?
Drop the file onto the box, leave The whole file selected, press Play the result to hear it backwards, and press Reverse and export WAV to save it. The first sound you hear is the last sound of the original, and the track ends where the original began.
Can I reverse only one section of a track?
Yes. Choose Only a part of it, then set a start and an end in seconds. Everything before the start and after the end stays exactly as it was, and only the part between plays backwards. The file keeps its full length, so it still lines up with a video or a mix you cut it from.
What is reversed audio good for?
The classic uses are a reversed cymbal or a reversed reverb tail, which build into a hit instead of fading after it, and a reversed phrase used as a transition or a texture. People also reverse a clip to check how a mix sounds with the usual cues removed, or to make an eerie effect from a voice.
Does reversing change the pitch, the speed or the length?
No to all three. The same samples are played in the opposite order, so each note keeps its pitch and the file lasts exactly as long as before. What changes is the shape of every sound: an attack that was sharp becomes a slow swell, and a decay that was gradual becomes a sudden stop.
If I reverse a file twice, do I get the original back?
Yes, sample for sample, as long as you keep the same settings. Reversal only reorders the samples, so doing it twice puts each one back where it started. The one difference is the format: the original may have been an MP3, and what you get back is a WAV of the decoded sound.
Is there a hidden message in a reversed song?
Do not expect one. Reversing speech or music gives sounds that the ear is eager to turn into words, which is why reversed recordings so often seem to say something. That effect is a property of listening, not of the file, and the tool has no way to tell you whether anything was put there on purpose.
Why is the reversed file so much bigger than my MP3?
The export is an uncompressed 16-bit WAV, and an MP3 is compressed, so a minute of sound takes roughly ten times the space. A WAV needs no encoder to download and adds no new loss. It is the same length as the original and about 10 MB a minute for stereo at 44,100 Hz.
How long a file can I reverse?
It opens files up to 150 MB and 15 minutes and writes a WAV up to 100 MB, about 9.9 minutes of stereo at 44,100 Hz. Because a reversal never changes the length, a track that is too long to write is refused with its size and the limit stated; cut it shorter first and reverse the part you need.
Does the reverser send my audio anywhere?
No. The file is read by your browser, reordered by code running in your browser and saved back to your device. The page makes no request with your audio, there is no upload and no account, and the code that does the reversing contains no network call. Closing the tab clears it.
May I reverse a recording I do not own?
Only if you have the right to use it. Use audio you made or have permission to use. A reversed copy of a commercial recording is still a copy, and posting it can infringe the copyright even though it sounds different. The tool cannot tell whose audio a file holds, so the check is yours.
Backwards is the effect. The video is the finished piece
Attach the track and describe the look. An AI director storyboards it scene by scene and renders it to your audio. Plans from $19/month, and you see the cost before anything renders.
Start your videoMore tools: Audio cutter · Audio joiner · Volume booster · Audio loop maker · Audio visualizer · BPM finder