Sample-accurate reversal via ffmpeg's
Sample-accurate reversal via ffmpeg's areverse filter
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Audio Reverser
Reverse any audio file so it plays backwards. Drop MP3, WAV, M4A, OGG or FLAC, choose output format, and download. ffmpeg.wasm areverse — no upload.
About Audio Reverser
Audio Reverser plays an audio file backwards. Drop in an MP3, WAV, M4A, OGG or FLAC file, pick an output format, and download the reversed track. Internally the tool runs ffmpeg's areverse filter, which loads the entire file into memory, flips the sample order, and re-encodes the result — so the start of the input becomes the end and vice versa. The whole pipeline runs locally via ffmpeg.wasm: files never leave your device, and there is no signup, watermark or daily limit. Reversing audio is a creative effect (think reversed cymbals, backward vocal builds, hidden messages), a sound-design technique (reverse-tail reverb to create a swell effect), or just a way to satisfy curiosity about what your favourite track sounds like inside-out. The tool ships at full quality — no resampling or bit-depth degradation beyond what your chosen output format requires.
Why use Audio Reverser
Preserves source quality
Preserves source quality — no resampling beyond the chosen output format
100% browser-side
100% browser-side — files never leave your device
Free
Free, no signup, no watermark
MP3
MP3, WAV, OGG and M4A outputs cover every mainstream player
Cached engine
subsequent reversals start instantly
How to use Audio Reverser
- Click or drag your audio file onto the upload area.
- Pick the output format — WAV for lossless, MP3 for compatibility, M4A or OGG otherwise.
- Set the bitrate (ignored for WAV, which is lossless).
- Click 'Reverse & Download' and wait for ffmpeg.wasm to finish.
- Audition the reversed result in the inline player.
- Click Download to save the reversed file to your device.
When to use Audio Reverser
- Creating a reverse-cymbal swell for a song intro
- Producing a 'backwards vocal' creative effect
- Building a reverse-tail reverb element for sound design
- Reversing a sound effect for video edit transitions
- Investigating 'hidden message' rumours in a track
- Making palindrome audio (combine reversed + original) for art projects
Examples
Reverse cymbal swell
Input: Cymbal crash (3s WAV, hit at 0:00, decay through 0:03)
Output: Reversed WAV — silence builds into a cymbal hit, perfect for song intro
Reverse vocal
Input: 30s vocal phrase MP3
Output: Reversed MP3 — backward vocal effect ready for a creative arrangement
Sound effect transition
Input: Whoosh.wav (forward sweep)
Output: Whoosh-reversed.wav — sweep going the other direction for a different transition feel
Tips
- For reverse reverb, take a vocal phrase, reverse it, run it through a reverb plugin, then reverse the wet output again — the reverb tail now sweeps into the dry sound.
- Reversing affects timing perception. A drum loop reversed often sounds 'wrong' even when it shouldn't — you're hearing the attack envelopes flipped.
- WAV output preserves the reversed audio bit-perfectly. MP3 / OGG / M4A re-encode and add small lossy artifacts.
- Reversing a stereo file flips both channels independently, so panning gestures play in reverse too.
- Long files take longer because ffmpeg loads the whole stream into memory. Trim the section you actually need first using the MP3 Cutter tool.
Frequently Asked Questions
Is the reversal lossless?▾
The flip itself is lossless. If you pick MP3, OGG or M4A as the output, the re-encoding step adds the usual lossy artifacts. WAV preserves everything exactly.
Will my file be uploaded?▾
No. ffmpeg.wasm runs locally in your browser; the file never leaves your device.
Can I reverse a video's audio track?▾
Not directly. Extract the audio first (any audio extractor) and feed the audio file in here.
Does reversing change the duration?▾
No — the duration is identical, only the playback direction is flipped.
Why does it take longer for big files?▾
areverse needs to hold all samples in memory to flip them. Multi-hour files use lots of RAM and can be slow; trim first if you can.
Are stereo channels reversed independently?▾
Yes — left becomes left-reversed, right becomes right-reversed. Panning gestures play in reverse.
Is there a maximum file size?▾
No server cap. Browser memory limits the practical size; multi-hour reversals work but may be slow.
How do I make reverse reverb?▾
Reverse the dry signal, run it through a reverb plugin in any DAW, then reverse the wet output here again — the tail sweeps into the dry hit.
Explore the category
Glossary
- areverse
- ffmpeg audio filter that reverses the entire audio stream — the last sample becomes the first.
- Sample-accurate
- Operating at the level of individual samples (no rounding or interpolation). Reversal is exactly bit-flipped.
- Reverse reverb
- Sound design technique: reverse audio, apply reverb, reverse again. The reverb tail sweeps into the dry hit instead of decaying after.
- Lossless output
- WAV preserves the reversed samples exactly. Lossy formats (MP3, OGG, AAC) re-encode and add small artifacts.
- Bit depth
- Bits per sample — 16-bit is standard for distribution; 24-bit for production.
- Channel-independent reversal
- Each channel reverses individually, so stereo placement also plays in reverse.