How to Completely Disable the ‘Startup Chime’ Sound on macOS Using Terminal

The iconic Mac startup chime (the loud, synthesized F-sharp major chord) has been a staple of Apple computers since 1991. While it is nostalgic for many, it is incredibly annoying if you are trying to turn on your laptop in a quiet library, a crowded lecture hall, or a sleeping household.

Apple famously removed the chime entirely from their laptops in 2016, only to controversially reintroduce it by default in macOS Big Sur and later updates. If you want your Mac to boot up in complete, stealthy silence, you can permanently disable the startup chime using a hidden system command in the Terminal.

Step 1: Disable the Chime via NVRAM

The startup chime is not controlled by the standard macOS sound preferences because the sound plays before the operating system fully loads. It is actually controlled by a hardware variable stored in the Mac’s NVRAM (Non-Volatile Random-Access Memory).

1. Open the Terminal app (found in Applications > Utilities, or via Spotlight search).
2. Copy and paste the following command exactly as written:

   sudo nvram StartupMute=%01

3. Press Return.
4. Because you are modifying low-level hardware memory (using the sudo command), the Terminal will prompt you for your Mac login password. Type it in and press Return. (Note: When typing passwords in Terminal, the cursor will not move, and asterisks will not appear. Just type it blindly and hit Return).

Step 2: Test the Results

The change is written directly to the motherboard’s memory and takes effect immediately.

1. Click the Apple logo in the top-left corner of your screen.
2. Select Restart…

When the screen goes black and the Apple logo reappears, your Mac will boot in absolute silence.

How to Restore the Startup Chime

If you are troubleshooting a hardware issue (Apple Geniuses often use the chime to verify that the logic board is receiving power and has passed its initial POST check), you will need to turn the sound back on.

1. Open the Terminal app.
2. Paste the following command to restore the default behavior:

   sudo nvram StartupMute=%00

3. Press Return, enter your administrator password, and reboot. The classic chime will return on the next startup.

Alternative Method (macOS Big Sur and Later)

If you are running a very recent version of macOS and do not want to use the Terminal, Apple did finally add a graphical toggle for this setting, though it is buried deep in the menus.

1. Open System Settings (or System Preferences).
2. Click on Sound.
3. Under the “Sound Effects” tab, look for a toggle switch labeled “Play sound on startup.” Turn this switch off to silence your Mac.