Fix · Slack on a Mac

Slack huddle mic not working? Fix it on your Mac.

Slack huddles use their own mic choice, and another calling app can take away Slack's mic access without telling you.

Quick check first: Try the free mic test. If the meter moves, your mic works and the fix is in Slack (steps 1 to 3). If not, start with the Mac checks.

Fix it in Slack

Pick the mic in Slack.Click your profile picture, then Preferences › Audio & video. Under Microphone, choose your mic, say a few words, and watch the level move.
Run Slack's test.On the same page, under Troubleshooting, click Run test. It works in the desktop app and in Slack in Chrome.
Use the huddle troubleshooter.During a huddle, click the troubleshooting icon at the bottom left. A warning icon there marks the problem.

Another calling app took the mic

Slack's help says other calling apps can revoke Slack's microphone access. Turn Slack off and on again in Privacy & Security › Microphone, then quit and reopen Slack.

Slack in the browser

If the desktop app won't work, Slack suggests trying your workspace in Chrome, or the other way around. In Chrome, make sure your workspace isn't blocked under Settings › Privacy and security › Site settings › Microphone.

Then check your Mac

If Slack looks right and the microphone still doesn't work, go through these in order.

Allow Slack on your Mac.Choose Apple menu › System Settings › Privacy & Security › Microphone, and turn on Slack. If it's already on, turn it off and on again. Quit and reopen Slack after.
Check your Mac's input.Open System Settings › Sound and click Input. Select your mic, make sure the Input volume slider isn't at zero, and watch the level move when you talk.
Check the mic itself.Look for a mute button, a mute light, or a gain knob turned all the way down. Unplug a USB mic and plug it back in, try another port, and skip the hub if you can.
Watch for Bluetooth call mode.When Slack turns on the mic in AirPods or another Bluetooth headset, the headset switches to call mode and your voice drops to phone quality. If you sound muffled, use your Mac's mic or a USB mic, and keep the headset for listening.

Test it outside Slack

The free microphone test runs in your browser, with nothing to install. If your microphone works there, your Mac and the hardware are fine, and the fix is in Slack's settings above.

Microphone testLive meter, then hear yourself back. Webcam testLive preview, resolution, frame rate, and lighting. Speaker testLeft, right, and a sweep to check every speaker.

On a Mac? See which mic Slack is really using.

Slack keeps its own mic choice, so your Mac can look right while the call uses the wrong one. Green Room shows which app has each mic open, and warns you when Slack isn't using your setup. One click switches your Mac back, and it flags a mic that's muted, at zero, or silent. Free, with no account.

Download free See how it works

Slack is using MacBook Pro Microphone, not Shure MV7.

Switch to Shure MV7

Questions

Why can't anyone hear me in a Slack huddle?

Open Preferences › Audio & video and pick the mic you're using, then click Run test. If Slack shows no level, turn on Slack in System Settings › Privacy & Security › Microphone.

How do I test my mic in Slack?

Open Preferences › Audio & video and click Run test under Troubleshooting.

My Slack mic stopped working after I used another call app. Why?

Slack says other calling apps can revoke its mic access. Turn Slack off and back on under Privacy & Security › Microphone, then reopen Slack.

Other fixes

Slack huddle audio not workingIf a huddle is silent, Slack is likely playing to a different speaker, or your connection is dropping the sound. Zoom microphone not workingWhen nobody can hear you, it's usually one of four things: Zoom never joined audio, it's using the wrong mic, you're muted, or macOS is blocking zoom.us. Teams microphone not workingTeams can be muted in three places at once: the meeting, your headset, and macOS. Google Meet mic not workingMeet hears your mic only if the site, the browser, and your Mac all allow it. Discord mic not workingDiscord's mic can pass its own test and still send nothing, because Push to Talk or input sensitivity decides when you're heard. FaceTime microphone not workingFaceTime has its own mic choice and its own Mic Mode.

See every app and device