Microphone not working in Slack
When your mic works elsewhere but not in Slack, the culprit is usually the input device chosen inside Slack or a missing permission. Confirm the mic works first, then fix Slack.
Step-by-step fix
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First, confirm the mic itself works: run the CheckMyMic microphone test.
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In Slack, open Preferences → Audio & video → Microphone and select the correct input device.
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Check the input level and make sure you're not muted inside Slack.
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Grant Slack microphone permission at the operating-system level.
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Restart Slack and rejoin your call.
Frequently asked questions
My mic works in the browser test but not in Slack — why?
That points to Slack's own device settings. Open Preferences → Audio & video → Microphone and pick the same microphone that worked in the test.
Does Slack need separate mic permission?
Yes — even if your browser or system has access, Slack may need its own grant. Allow it in your OS privacy settings, then restart Slack.
Everything looks right but Slack still can't hear me — what now?
Update or reinstall Slack — device lists go stale after OS updates. Run the CheckMyMic mic test again to prove the mic itself, then check our mic guide for your operating system (Windows, macOS, and the rest): an OS-level permission or default-device change fixes this more often than anything inside Slack.
Why doesn't my mic work in a Slack huddle?
Huddles use Slack's own device pick, which can lag behind a newly plugged-in headset. In the huddle window click the gear icon (or Preferences → Audio & video) and re-select your microphone — the small input meter there should move when you speak.