Reverse WAV online

WAV is the file you bounce when you do not want a surprise codec. PCM inside a RIFF wrapper, sometimes with extra chunks. This page reverses that audio in the browser: upload, decode, reverse the buffer, preview, download a WAV. It is the right tool for short effects, voice takes, and session bounces that already live as WAV. It is a strained tool for multi-gigabyte stems on a phone.

If you came from a compressed original, start on MP3 reverser or reverse M4A instead. If you have FLAC, FLAC reverser covers the lossless-but-smaller case. For “I want the cleanest reverse I can get in this tab,” also see reverse audio high quality. Sound-effect habits are on reverse sound.

PCM, not a special WAV trick

WAV usually means linear PCM: a list of amplitude values. Reversing PCM is the operation people imagine: last sample first. Some files named .wav are not PCM. WAVE_FORMAT_EXTENSIBLE, float files, RF64, and odd ADPCM variants depend on what the browser’s decoder allows. If decode fails, convert to a 16-bit or 24-bit PCM WAV in an editor and retry.

BWF (Broadcast Wave) is WAV plus a bext chunk: origination date, time reference, description. Field recorders write BWF so picture can sync later. This site reads samples, not the bext chunk. After reverse, your download will not carry the original timestamp. If you need BWF out, reverse in a tool that rewrites bext, or reverse here and wrap metadata again in a DAW.

Browser memory is the real limit

A minute of stereo 48 kHz 24-bit is already several megabytes uncompressed. A feature-film stem is hundreds of megabytes to gigabytes. The Web Audio path keeps the decoded buffer in RAM, then allocates another buffer (or an in-place reverse) for playback. Phones kill the tab when that working set is too large. That is not a server quota. Nothing is uploaded. It is your device running out of heap.

Practical habits:

• Crop to the region you actually need before upload.
• Prefer desktop Chrome or Firefox for files over roughly 100 MB.
• Close other tabs that hold video.
• Do not expect a 2-hour board mix to reverse on an old iPhone.

Recording from the microphone is capped at 60 seconds and is unrelated to WAV size on disk; it is a capture limit. For long material, upload a file you already trimmed.

24-bit versus 16-bit after decode

Editors argue about word length. Inside the browser, AudioBuffer channels are 32-bit floating point. A 16-bit WAV is converted up on the way in. A 24-bit WAV is also converted to float. The download is written from that float buffer as a WAV. You should treat the result as a working copy, not a bit-identical archive of a 24-bit master.

Consequences:

• Dither from the original 16-bit file is reversed along with the music. That is correct and slightly odd to stare at in a waveform.
• If you need a 24-bit integer reverse for delivery, do the reverse in a DAW set to 24-bit, from the same master.
• Peak values near full scale can clip in float-to-integer writes if the source was already hot. If the reversed file clicks at peaks, lower the source or reverse in an editor with headroom.

This page does not offer a bit-depth picker. Keeping the UI to reverse, preview, and WAV out avoids implying a mastering chain that is not here.

Steps for a WAV or BWF

1. Export or bounce PCM WAV if you still can. Avoid “WAV” that is actually MP3 in a fake wrapper.
2. Upload. Allowed types include MP3, WAV, FLAC, OGG, M4A, and AAC; this article assumes you brought WAV.
3. Wait. Large PCM takes time to read from disk into JS memory.
4. Play from the end of the original timeline. Switch between Play reversed and Use original.
5. Use 0.5x–2x preview to inspect a transient. Preview speed is not printed.
6. Download. Check the start of the new file; the original tail is now the attack.

No YouTube URL. No song ID database. No polarity invert.

Clicks at the new attack

WAV bounces often start at zero and end on a reverb tail that does not sit at zero. After reverse, that tail is the new start, which is fine, but a non-zero opening sample of the original becomes the new end, which can click. The site applies a short fade at the edges to reduce that. A round trip (reverse twice) is therefore not bit-identical to the first original. Keep the first WAV.

If you need a click-free film stem, fade the source before upload or trim after download.

Ambisonics, surround, and odd channel counts

Stereo reverses as two independent channels, left stays left. Multi-channel WAV support depends on the browser. If a 5.1 file collapses or fails, split to stereo or stems in a DAW, reverse the stems you need, and reassemble. Do not assume 7.1 BWF from a set will survive a phone browser.

When WAV is the wrong upload

If the file is a Voice Memo, it is probably M4A. If it is a WhatsApp note on Android, it may be OGG. Uploading those as-is is fine; the decoder will handle the real codec. Renaming .m4a to .wav will not.

Use WAV when you already have PCM and you care about the transient. Use this page when you want that PCM backwards without installing a DAW for a one-off. Use a DAW when the file is huge, tagged BWF, or must remain 24-bit integer end to end.