The short answer: it's usually one of three things. Dictation is off or on another shortcut, the Mac is listening to the wrong microphone, or Voice Control is on (it replaces Dictation). Check those first.
1. Check that Dictation is on
Open System Settings, click Keyboard, and make sure Dictation is turned on.
2. Check the shortcut
In the same place, look at Shortcut: that's the key that starts Dictation. If you expect the fn (🌐) key to start it, check Press 🌐 key to in Keyboard settings: it may be set to show emoji or change the input source. And if another dictation app uses the same key (Featherweight Dictation, Wispr Flow, Aqua Voice and Willow Voice all use fn), give one of them a different key.
3. Pick the right microphone
Open System Settings, then Sound, then Input. Choose the microphone you talk into (the built-in one is fine), and watch the input level move as you speak. If it barely moves, raise the input volume. An external microphone needs to be connected and selected here.
4. Turn off Voice Control
Voice Control, an Accessibility feature, replaces Dictation while it's on. Open System Settings, then Accessibility, then Voice Control, and turn it off.
5. Check the language
Dictation listens for the language set in its settings. If it types nonsense, it's probably listening for another language: set the one you speak under Keyboard, then Dictation.
6. Check the internet
On Intel Macs, and in languages Apple doesn't process on the device, your voice goes to Apple's servers, so Dictation needs a working connection.
7. Cut the background noise
Keep the microphone uncovered, speak clearly, and move away from noise, or use a headset. A fan, music or a busy room can stop Dictation from hearing where your words end.
8. Turn Dictation off and on again
Switch Dictation off in Keyboard settings, wait a few seconds, and switch it back on.
9. Restart your Mac
A restart clears a stuck microphone or a speech service that stopped answering.
10. Update macOS
Open System Settings, then General, then Software Update. Dictation gets fixes with macOS updates.
If you use Featherweight Dictation
- Nothing happens when you hold the key: check that it's running (its sound bars are in the menu bar), and that it's switched on under Privacy & Security for both Accessibility and Microphone. After a macOS update, switching it off and on again there can help.
- Holding fn opens emoji or switches the keyboard: in Keyboard settings, set Press 🌐 key to to Do Nothing, and give macOS Dictation a shortcut other than fn.
- You can't see the menu bar icon: macOS hides icons when the menu bar is full. Open Featherweight Dictation again from Applications and its window appears.
- Still stuck: the help center has more, or write to hello@featherweightsoftware.com and a person will get back to you.