How to reverse audio on a Mac

On a Mac you reverse audio in the browser the same way as on any desktop: the page decodes MP3, WAV, FLAC, OGG, M4A, or AAC, plays the AudioBuffer from the last sample to the first, and offers a WAV download. Processing stays in the tab. Safari and Chrome are both fine. This is not a Mac App Store application and not a GarageBand template.

GarageBand (and Logic) can reverse a region on a timeline. That is the heavier option when you already have a session, need fades, or must reverse eight bars of a vocal without flipping the drums. This page flips the entire file. If that is all you need, stay here and leave GarageBand closed.

Windows steps are how to reverse audio on PC. iPhone capture that later lands on the Mac is how to reverse audio on iPhone.

Safari and Chrome on macOS

Safari: allow the microphone under Safari → Settings → Websites → Microphone if you will record. Downloads go to the folder in Safari → Settings → General.

Chrome: allow the mic from the address-bar padlock when prompted. Chrome’s Downloads path is independent of Safari’s. Do not assume both browsers write to the same directory.

Either browser can run out of RAM on a long stereo WAV; Activity Monitor will show the tab’s process. Close other tabs. A Mac with 8 GB or more usually handles a typical song. A 2-hour mixdown is a job for an editor that streams from disk, not this page.

The page must be HTTPS. A file:// copy of the site will not get a mic. You do not paste a file URL into a text field; use the file picker. There is no fetch of an iCloud share link.

Files from Finder

Typical sources:

• Downloads from a browser or Mail.
• Voice Memos synced via iCloud Drive (wait until the cloud icon clears).
• AirDrop from iPhone (usually M4A).
• Export from an editor: WAV or AIFF. AIFF may fail in some browsers; bounce WAV or FLAC if the picker rejects AIFF.
• CD rips as FLAC or MP3.

Finder aliases: the picker may follow the alias or fail. Use the real file. Files with quarantine attributes from the internet still reverse; quarantine affects launch of apps, not decode of audio in a web page.

Drag-and-drop onto the upload control works in Chrome and often in Safari; if it does not, click Upload. Multiple selection is not a batch reverse. One file per decode. Format-specific notes: WAV reverser, FLAC reverser, MP3 reverser.

Do not change a .m4a extension to .wav in Finder. The bytes stay AAC. The decoder keys off the container.

GarageBand as a heavier alternative

GarageBand on Mac can reverse a region: select the region, open the editor, enable Reverse where Apple currently places it (the control has moved between versions). Use that when:

• Only part of a take should run backwards.
• You need the reversed vocal aligned to a click.
• You already live in that project.

GarageBand is not a partner of this site. It is Apple’s DAW. It will not download a one-click WAV from this editor into a track automatically; you import the WAV yourself.

Logic, Audacity, and Reaper also reverse regions. Same story: timeline tools for sessions, this page for a whole buffer. Audacity on Mac is covered in spirit by the PC article; the Effect → Reverse menu is the same program.

Recording on the Mac

Record on this page: 60 seconds, getUserMedia, permission prompt. Built-in Mac mics are distant. A USB mic or headset is cleaner. Aggregate devices in Audio MIDI Setup can confuse a browser; pick a single input in the OS before you hit Record.

If you need longer than 60 seconds, record in QuickTime Player, Voice Memos, or GarageBand, save a file, then upload. QuickTime’s .m4a is a normal upload.

Do not monitor through speakers while recording; the room will reverse into the take. Use headphones.

Preview 0.5x–2x is not printed into the WAV. Pitch does not change.

After download

The WAV lands in Downloads unless you redirected it. Import into iMovie, GarageBand, or a video editor if you need picture. This site does not reverse video.

To restore original order, upload the WAV and reverse again. Keep the Finder original.

iCloud Desktop & Documents: if Downloads is synced, the WAV will upload to iCloud after save. That is the OS, not this page sending audio to a server during reverse.

What the Mac browser path will not do

• Fetch a URL you drop in the dock.
• Pitch-shift or translate.
• Reverse a highlighted region of a file (trim in QuickTime first, then upload).
• Batch a folder of FLACs in one click.

For a folder of files, use an editor with a batch chain, or reverse them one at a time here. Closing the tab discards an undownloaded buffer.