Help with RedLight — recording system audio on your Mac

Setting up the first time

Two minutes, once. After this you can just open and record.

1. Open RedLight

   Find it in your Applications folder (or Launchpad) and click to open. The main window appears with a large red button at the bottom.

2. Allow it to record when macOS asks

   The first time you record, macOS shows a permission box. Click Allow (or OK). This is macOS keeping you in control — RedLight can't capture any sound until you say yes.

3. If you clicked the wrong button by mistake

   No problem. Open the Apple menu → System Settings → Privacy & Security, find RedLight under the audio recording permission (Microphone), switch it on, then quit RedLight and open it again.

Making a recording

The key thing to know: RedLight records whatever is already playing through your Mac. So start the sound first.

1. Choose where the file should go

   Near the bottom of the window you'll see a file name and a Change… link. Click it to pick a folder, such as your Desktop. RedLight needs a folder set before it can record.

2. Start the sound you want to capture

   Play the video, call, app, or instrument you want to record, at a normal listening volume. If nothing is playing, there's nothing for RedLight to hear.

3. Click Start recording

   Press the big red Start recording button (or press ⌘R). The timer begins counting and the two bars in the middle move as sound comes through — that's how you know it's working.

4. Click Stop when you're done

   The same button now says Stop. Click it, and your recording is saved automatically as a file.

Recording your own voice as well

New in version 1.1. RedLight can capture your microphone alongside the system audio — for calls, meetings, voice-overs and commentary. It stays off until you turn it on.

1. Switch the microphone on

   In the main window open Sources and turn Microphone on — or click Microphone in the menu bar, which reads Enabled or Disabled at a glance. Choose which input to use under Input, or leave it on System default.

2. Choose how it's saved

   Record as → Stereo Mix writes one file with your voice summed into the system audio. Separate File writes two files of the same length — the system audio under the usual name, your microphone beside it ending in -mic — so you can set the balance afterwards.

3. Let RedLight set the level, or set it yourself

   Auto level is on to start with: it measures only while you're actually speaking, brings your voice up to a good level and balances it against the system audio when there is any — a quiet room is never lifted to meet it. Turn Auto level off and the Mic level fader is yours. System level sets how loud everything else sits under your voice.

4. Wear headphones

   Otherwise the microphone picks up your speakers too, and the system audio lands in the recording twice.

Finding and playing your recordings

Every recording is a normal audio file you fully own.

1. Find the file

   It's saved to the folder shown by the Change… link, and it also appears in the Recent Recordings list inside RedLight (the last 20). Files are named by date and time, for example RedLight-2026-07-06-22h56.wav.

2. Play or reveal it

   Double-click the file to open it in your Mac's built-in player, or use the Recent Recordings list in RedLight to play or reveal any past recording in the Finder with one click. A WAV file is a standard, high-quality format that plays in QuickTime, Music, and almost any audio app.

Handling silence

RedLight can deal with quiet gaps automatically. Choose the behaviour in Settings.

Choosing what to record

By default RedLight captures all the sound coming out of your Mac. In Settings you can instead record only chosen apps, or record everything except certain apps — handy for leaving out notifications or a music player while you capture a call.

Hands-free capture

RedLight can live in your menu bar and run without the main window. The menu does the everyday work: Record, Stop and a Microphone toggle reading Enabled or Disabled — those three leave the menu open when you click them, so you can arm the mic and start recording without reopening it — plus a status line, the recordings folder, and the full window.

Two optional settings make it fully hands-off:

Microphone and levels

System audio is captured whether or not the microphone is on — the microphone is an extra, and it's off by default. Everything below lives in Sources, under the Microphone switch.

Formats and quality

RedLight records to WAV by default — a standard, high-quality format that plays in QuickTime, Music, and almost any app, and drops straight into a DAW. In Settings you can choose a different format and quality to suit your workflow:

• Uncompressed: WAV, AIFF, CAF
• Lossless compressed (smaller, no quality loss): ALAC, FLAC
• Compressed (smallest files): AAC, with a choice of bitrates

You can also set the bit depth (16, 24, or 32-bit float) and either match your source's sample rate or pick your own.

Automatic housekeeping

For long or unattended sessions, RedLight can keep things tidy on its own. Both features are off by default — turn them on in Settings only if you want them.

Split long recordings automatically

RedLight can break a long session into a series of files by time (e.g. every 60 minutes) or by size (e.g. every 500 MB), so you're never left with one giant file.

Clean up old recordings automatically

RedLight can remove older recordings once they pass a limit you set — either an age (older than N hours) or a total folder size (delete the oldest until the folder is back under your cap). Useful for a machine that records around the clock.

RedLight Unlimited

The free version records up to four minutes at a time. One purchase removes that limit forever.

Troubleshooting

The most common hiccups and how to fix them.