Reverse audio with a microphone

The microphone button on this site is a timed capture into the same reverse engine as an upload. You get at most 60 seconds, then time-reversed playback, then an optional WAV download. This page is about the capture side: which mic, how permission works, how to monitor, and when to stop using the mic and upload a file instead.

It is not a driver pack, not a USB mixer, and not a way to reverse a Zoom call in real time.

Permission

Browsers treat the microphone as a powerful permission. The first Record press shows a prompt naming this site. Allow once or always, depending on the browser.

If you clicked Block, Record will fail until you reset the permission:

• Chrome / Edge: padlock → Site settings → Microphone.
• Firefox: permissions in the address-bar control.
• Safari: Safari Settings → Websites → Microphone.

file:// pages and some in-app browsers (Instagram’s internal browser, some WebViews) never get a reliable mic. Open the site in a real Chrome, Firefox, Safari, or Edge window.

HTTPS is required. This site is served over HTTPS; a copied HTTP link may be blocked.

Windows exclusive mode: an ASIO DAW or a voice chat app can lock the device. Close that app or switch Windows sound settings so the mic is shared. The reverse page cannot steal an exclusive lock.

iPhone Safari: permission is granted per site. Low Power Mode and Call audio routes can reroute the input. If Record captures silence, check you are not in a phone call and that the correct mic is not covered by a case. How to reverse audio on iPhone covers Voice Memos as the better long-form path.

Android: Chrome needs the OS mic permission for the browser app as well as the site prompt. How to reverse audio on Android.

Mic choice

Laptop capsule. Fine for speech jokes and humming. Noisy fans will reverse into odd swells. Sit close.

Phone. Often a better capsule than a cheap laptop. Use the phone browser, or record in the stock recorder / Voice Memos and upload. Upload is more reliable for anything you might keep.

USB headset. Predictable speech, poor for singing room tone. The boom should sit off-axis to plosives; reversed plosives become strange tails.

Audio interface. Select it as the browser’s input in OS sound settings before you hit Record. Browsers typically do not expose a full input-gain panel. Set gain on the interface. If you need 24-bit / 96 kHz masters, record in a DAW and upload WAV; the tab capture is whatever the browser’s AudioContext runs at (often 48 kHz).

This page does not list sample-rate options. It does not apply a broadcast limiter. It time-reverses the buffer it got.

Stereo versus mono: many mics arrive as stereo with duplicated or near-duplicated channels. Reverse does not swap L and R. Flip audio is about time, not stereo image.

Monitoring

If reversed playback is running on speakers while you record a second take, you are recording the speakers. Use headphones.

Some systems offer hardware direct monitoring on an interface. That is the dry input, not the reversed output. You will not hear reverse in realtime through direct monitor—and you should not expect to. Reverse needs the take to finish (or at least to have samples) before a full-file reverse makes sense. This product reverses the completed buffer, not a live backwards-through-the-mouth effect.

Latency: Bluetooth headsets add delay. For a 60-second sketch it is tolerable; for tight rhythmic claps, use wired.

When 60 seconds is the wrong tool

Lectures, songs, and podcast ads should be recorded elsewhere and uploaded. Formats: MP3, WAV, FLAC, OGG, M4A, AAC. The general capture-plus-reverse workflow is reverse audio recorder. Speech-focused notes: reverse voice recorder. Existing iPhone files: reverse Voice Memo.

Speed preview after capture is for listening, not for printing a slow reversed performance. Download WAV, then change rate in an editor if needed.

Processing is local. Closing the tab drops an undownloaded take. There is no cloud recents list.

Practical checklist

1. Headphones on.
2. Correct input selected in the OS.
3. Permission allowed for this origin.
4. Room as dry as you can get if you plan a second reverse later.
5. Record, stop before 60 seconds, play reverse, A/B with Normal.
6. Download WAV or re-take.

If Record stays dead after that list, the mic problem is OS or hardware, not a missing “pro mode” on this page.

Linux, Bluetooth, and sample rate

Linux: Chromium needs Pulse/PipeWire to expose the device. Flatpak browsers sometimes see no mic until permissions are granted to the sandbox. Firefox has a separate about:preferences permission list.

Bluetooth headsets on laptops often switch to the HFP profile when a site asks for the mic, which dumps you to 8 kHz telephony. Reverse will not restore bandwidth that HFP discarded. Use a wired mic or disable the headset mic and use the laptop capsule.

The AudioContext rate is commonly 48 kHz. That is adequate for speech sketches. It is not a reason to skip a dedicated recorder for music.

After the take

Download immediately if the line is good. Refreshing the page to “fix permission” drops the buffer. Normal/Reverse A/B does not replace a WAV on disk.

If you need several takes, this is still not a playlist recorder. Download or lose them. The 60-second cap is per press, not a budget you can bank across the day.