Guide

Mac volume keys not working: why, and the fixes

Last updated: October 2, 2026 · By Taha Bozdemir, who builds EQBase

Most of the time this is not a fault: your Mac's current sound output doesn't accept a volume command, so macOS disables the keys on purpose. HDMI and DisplayPort displays, TVs, optical connections and many USB interfaces are fixed-volume: they take the audio as a digital stream at full strength, and the level is decided at the other end, by the display, the receiver or the DAC. macOS greys out the volume slider and puts the prohibited symbol under the volume icon because there is genuinely nothing for the keys to change. The fixes: change the volume where it actually lives (the device's own controls), command the display directly over DDC (MonitorControl does this, and so does EQBase), or put a software volume into the signal path on the Mac and point the keys at that, which EQBase also does. If the keys produce no bezel at all, that's a different and rarer problem, covered at the end.

Below: how to tell which case you're in, why macOS behaves this way, and what each fix costs.

First, which of these is happening?

• The bezel appears with a prohibited symbol (a circle with a slash under the speaker): you're on a fixed-volume output. This is the common case and the rest of this page is about it.
• The bezel moves but the loudness doesn't change: the volume is changing on a different device than the one playing. Check which output is selected in Control Center or System Settings > Sound.
• No bezel at all: a keyboard problem, not an audio one. See the last question below.

Why macOS greys out the volume keys

Every audio device reports to macOS whether it has a volume control. Analog outputs like the headphone jack and the built-in speakers do, so the keys work there. Digital connections usually don't: HDMI, DisplayPort and optical carry the audio as data, bit for bit, and the receiving device applies its own volume after converting it. Rather than show a slider that lies, macOS disables the control. Annoying, but honest.

Two more device types behave the same way and catch people out:

• Multi-Output and Aggregate Devices, the combinations recording tutorials have you build, have no master volume, which is why the keys die right after you set one up. (A recorder that reads the system mix directly never needs one; see how to record system audio on a Mac.)
• Many USB DACs and audio interfaces deliberately expose no software volume, on the theory that level belongs on their front panel.

Check your own device in a minute. Open Audio MIDI Setup (in Applications > Utilities), choose Window > Show Audio Devices and select your output. Apple's guide to that window says that "if software volume control is available for your device, the Volume sliders appear blue". If they are not active, macOS has no volume on that device to drive, and the keys stay dead. Apple's sound troubleshooting guide says the same of digital outputs in one line: "You can't use the computer's volume controls to adjust the volume while using digital output." For a USB DAC the answer is in the device itself: Apple's USB audio technote says macOS exposes the Volume control on the Feature Unit closest to the physical output, so a device whose descriptors declare no Volume control gets no slider, whatever cable it uses.

The fixes

1. Use the device's own volume

The TV remote, the monitor's buttons, the amp's knob. This is the cleanest option for sound quality, because the Mac keeps sending the untouched full-strength stream and the volume happens in one place, at the destination. The cost is ergonomic: the control is no longer on your keyboard, and monitor buttons in particular are usually awful.

2. Command the display over DDC

MonitorControl (free, open source) sends DDC commands over the display cable, so your volume keys change the monitor's own volume, the same setting its buttons reach. When it works it's the closest thing to the built-in behavior. The limits: displays only (it can do nothing for optical or a USB DAC), and TVs, some hubs and some adapters don't pass DDC through.

EQBase does the same thing per monitor, on the free tier: with an HDMI or DisplayPort monitor as your output, turn on Control this monitor's volume under Volume & balance in the Devices pane. From then on EQBase's volume slider, and the volume keys if you give them to EQBase (below), set the monitor's own volume over DDC/CI instead of attenuating the audio. The same cable and adapter limits apply, and it has been tested on Apple silicon Macs.

3. Put a software volume in the signal path

The third route is to attenuate the audio on the Mac, before it leaves. Digital attenuation is a clean multiplication of the samples (the same math covered in how to make your Mac louder, run in the other direction), so at normal listening levels it costs nothing audible. Any system-wide audio app with its own volume gives you the slider; what matters is whether it also puts the keys back on it, as EQBase, SoundSource, Sound Control and FineTune do.

Which apps restore the volume keys?

Software that restores the keyboard volume controls on an HDMI or DisplayPort monitor works in one of two ways. DDC tools change the monitor's own volume: MonitorControl (free, open source) and EQBase (free tier). Software-volume tools attenuate the audio on the Mac and give the keys that level instead: SoundSource's Super Volume Keys ($49, macOS 15+), Sound Control's Virtual Volume ($30, macOS 14.6+) and EQBase again. FineTune (free, open source, macOS 15+) does both.

eqVol (free, macOS 14.2+) takes the software route for HDMI alone, by installing a virtual audio device. Background Music, often suggested for this, adds no volume to a fixed-volume output as of version 0.5.0. Prices and features change; if something here is out of date, tell us.

Putting the volume keys back with EQBase

EQBase processes all system audio and keeps its own volume per output device, so on a fixed-volume output there is already a real level control in the path; it's just sitting in a window instead of under your fingers. The opt-in in Settings changes that: your volume keys, mute included, drive EQBase's volume for the current output, holding a key ramps, and you get a volume display instead of the "not allowed" bezel and chime.

Turning it on:

1. Switch your Mac to the output whose keys do nothing, so EQBase can see the problem it is being asked to solve.
2. Open EQBase's Settings, then the General tab, and find the Playback section.
3. Switch on Use the volume keys for EQBase.
4. macOS asks for Accessibility permission at that click. Grant it, and the keys start working: tap to step the level, hold to ramp, and the mute key mutes.
5. Nothing to undo when you switch back. On an output whose keys already work, EQBase stands down and never touches them.

Two deliberate design decisions:

• macOS will ask for Accessibility permission, once, at the moment you turn it on. Suppressing the system's "not allowed" bezel means consuming the keypress, and macOS rightly gates that behind a permission. EQBase never asks at launch, only at your click.
• It only takes the keys where they're already dead. On built-in speakers, a headphone jack or any output whose keys work, EQBase never intercepts anything. The feature arms itself exactly when macOS gives up on the keys, and stands down again when you switch to an output that handles them.

This is part of the free tier, which has no time limit.

Common questions

Why do my Mac's volume keys show a prohibited symbol?

The current output device told macOS it has no volume control. HDMI, DisplayPort and optical connections and many USB audio devices are fixed-volume: they carry the audio as data and the level is set at the receiving end, so macOS disables the keys rather than offer a control that does nothing.

What options exist for controlling volume on Mac optical and USB audio outputs?

There are three options for a Mac's optical or USB audio output, because DDC, the display route, only reaches monitors. Change the level after the Mac, on the receiver's or DAC's own knob or remote, which leaves the signal untouched. Attenuate on the Mac instead: EQBase's free tier, SoundSource's Super Volume Keys, Sound Control's Virtual Volume and FineTune add a software volume your keyboard keys can drive, and eqMac's free tier adds a volume slider. Or put a DAC or interface with a hardware volume knob between the Mac and your speakers.

How can I control HDMI monitor audio from my Mac keyboard while working at a desk?

Give the keys a volume they can reach: the monitor's own, over DDC, or a software volume on the Mac. In EQBase both are free. Select the monitor in the Devices pane, turn on Control this monitor's volume under Volume & balance, then turn on Use the volume keys for EQBase in Settings, General, Playback. The keys then change the monitor's own volume over the display cable, with a volume display instead of the prohibited symbol. If the monitor does not answer, which happens with TVs, some hubs and some adapters, leave that switch off and the keys drive EQBase's software volume instead. EQBase's monitor control has been tested on Apple silicon Macs. MonitorControl, free and open source, does the DDC half on its own.

How can I use Mac software volume control with a USB DAC whose keyboard volume controls are disabled?

Put a software volume in front of the DAC and point the keys at it. In EQBase's free tier, select the DAC as the output in the Devices pane, where the slider under Volume & balance becomes its volume, then turn on Use the volume keys for EQBase in Settings, General, Playback and grant Accessibility when macOS asks. The keys then step EQBase's volume for that DAC, holding a key ramps, and the mute key mutes. EQBase takes the keys only when the DAC exposes no volume of its own, so a DAC with a working hardware volume keeps its own keys. Attenuating in software is a clean multiplication of the samples, so at normal listening levels it costs nothing audible.

Why did my volume keys stop working after setting up screen or audio recording?

Recording guides often have you switch your output to a Multi-Output or virtual device, and combined devices have no master volume, so the keys grey out. Switching the output back in System Settings > Sound restores them, or use a recorder that reads the system mix directly and never needs the output switched; see how to record system audio on a Mac.

Why does EQBase need Accessibility permission for the volume keys?

To take over a key, EQBase has to consume the keypress; otherwise macOS still plays the "not allowed" bezel and chime over every press. macOS gates consuming keyboard events behind the Accessibility permission, and EQBase asks for it when you flip the switch, never at launch.

Does changing the volume in software reduce audio quality?

Attenuation is a multiplication of the samples, which is mathematically clean, and at normal listening levels the cost is inaudible. On a fixed-volume output the honest comparison is not against a hardware knob you don't have; it is against having no control at all.

My volume keys do nothing at all, not even a bezel. What then?

That's the keyboard, not the audio. On third-party keyboards the volume keys may arrive as plain function keys: check the function-key behavior in System Settings > Keyboard, and remap them with the vendor's software or a tool like Karabiner-Elements. Also check that a remapping tool isn't already capturing them.

Related

How to make your Mac louder · How to record system audio on a Mac · Per-app volume control on a Mac

Download EQBase free