Slack Mic Test & “Microphone Not Working” Fix

Step 1: Does your mic work at all?

Click Test my microphone above and speak:

• The bar moves here — your mic and drivers are fine; the problem is in your Slack settings. Go to Slack audio settings.
• The bar does not move here — the issue is system-level (permission, device or driver), not Slack. See System-level fixes.

Step 2: Fix Slack audio settings

Open Preferences → Audio & video, then:

1. Open Huddle/Call device settings. In a Huddle click the → settings, or go to Preferences → Audio & video.
2. Pick the right Microphone. Set Microphone to the device that worked above.
3. Unmute the Huddle. Click the mic button so it is not slashed; Huddles start muted by default in large channels.
4. Restart the Huddle. Leave and rejoin the Huddle to re-grab the mic if Slack lost the device.

Slack-specific gotchas worth checking

Slack mic problems almost always happen inside Huddles, and a Huddle does not re-read your device list mid-call — if you changed mics, leave and rejoin the Huddle. Huddles in large channels start muted by default, so the slashed mic button is expected; click it once to speak.

Slack also has two clients with separate audio settings: the desktop app and the browser tab. The browser version uses your site microphone permission, while the desktop app uses the OS-level permission — granting one does not grant the other. If the desktop Huddle is silent but the test on this page works, set the mic under Preferences → Audio & video and confirm Slack appears (allowed) in your OS microphone privacy list.

Step 3: System-level fixes (if the test above also failed)

If the volume bar did not move in the test, the problem is your device or OS, not Slack. Fix it here, then retest.

Windows 10 / 11

1. Settings → Privacy & security → Microphone: enable Microphone access and allow desktop apps (and your browser).
2. Settings → System → Sound → Input: select the correct device and confirm the meter moves.
3. Right-click the speaker icon → Sound settings → Recording: set your mic as the Default device and enable it.
4. Close other apps holding the mic (Zoom, Teams, Discord, OBS) and restart Slack.

macOS

1. System Settings → Privacy & Security → Microphone: enable Slack (or your browser), then quit (Cmd+Q) and reopen — macOS only applies the permission after a restart.
2. System Settings → Sound → Input: choose the right device and check the level.

Slack in the browser (web client)

If you joined Slack from a browser, click the mic icon in the address bar, choose Allow, and reload. The web client uses the same browser microphone permission as the test on this page.

Slack on phone (iOS / Android)

Open your phone Settings and enable the Microphone permission for Slack, then reopen the app and rejoin. In the call, tap the screen and confirm you are not muted.

Step 4: Last resorts

• Update Slack to the latest version (older builds have audio device bugs).
• Update or reinstall your audio/headset driver and reboot.
• Sign out and back in, or do a clean reinstall of Slack.
• On a USB headset, try a different port and confirm it is selected as both the microphone and speaker.

FAQ