AWDL: The Silent Latency Killer on macOS

TL;DR: If you’re experiencing random lag spikes on your Mac over Wi-Fi, AWDL (AirDrop’s wireless protocol) is likely the cause. I wrote a daemon that keeps it disabled permanently - even after sleep/wake cycles.

The Problem

I was getting frustrating mouse stickiness when using Synergy by Symless to share my keyboard and mouse across machines. The cursor would feel responsive for a few seconds, then stutter like skipped frames, then recover. Classic symptoms of network jitter.

I also noticed the same issue with Sunshine/Apollo game streaming - input lag that came and went in a regular pattern.

I wrote a quick Python script to measure LAN latency to my router every 200ms. The results were damning:

Those red spikes hitting 80-90ms every ~1.5 seconds? That’s not network congestion. That pattern is too regular, too predictable. Something on my Mac was interrupting the network stack like clockwork.

The Culprit: AWDL

AWDL (Apple Wireless Direct Link) is the protocol behind AirDrop, AirPlay, and Handoff. It works by periodically switching your Wi-Fi radio to a different channel to scan for nearby Apple devices.

During those scans, your normal Wi-Fi traffic waits. For ~80-90ms. Every 1-2 seconds.

The Evidence

I wrote a test script that toggled various macOS network settings and measured the impact:

AWDL was the only setting that mattered. Disabling it:

• 6x lower average latency
• 8x lower max latency
• 23x lower jitter
• Zero spikes

The Fix

Quick fix (temporary)

sudo ifconfig awdl0 down

This works immediately but macOS re-enables AWDL after every sleep/wake cycle.

Permanent fix (runs at boot)

I wrote a guard script that monitors AWDL and disables it whenever macOS turns it back on. Install it as a LaunchDaemon so it starts automatically at boot:

# Download the scripts
git clone https://github.com/adamlovattdevops/slow-wifi.git
cd slow-wifi

# Install
sudo cp awdl-guard.sh /usr/local/bin/
sudo chmod +x /usr/local/bin/awdl-guard.sh
sudo cp com.local.awdl-guard.plist /Library/LaunchDaemons/
sudo launchctl load /Library/LaunchDaemons/com.local.awdl-guard.plist

That’s it. The script now runs at every boot and catches AWDL reactivating within 5 seconds of sleep/wake.

What I tried first (doesn’t work)

Before writing the daemon, I tried:

• System Settings → AirDrop & Handoff → set to “No One” / Off
• defaults write commands to disable AirDrop and Handoff

Both work initially. But close your laptop lid, open it again, and AWDL is back. macOS re-enables it on every sleep/wake cycle regardless of your preferences. The daemon is the only fix that actually sticks.

Reverting (if needed)

sudo launchctl unload /Library/LaunchDaemons/com.local.awdl-guard.plist
sudo rm /Library/LaunchDaemons/com.local.awdl-guard.plist /usr/local/bin/awdl-guard.sh
sudo ifconfig awdl0 up

Human Perception Context

Why does this matter? Here’s where those latencies sit relative to human perception:

• 4ms (AWDL off): Imperceptible, feels like local
• 25ms (AWDL on average): Noticeable for fast interactions
• 93ms (AWDL spike): Clearly laggy, breaks flow state
• 100ms: Threshold where delay becomes consciously perceivable
• 250ms: Average human visual reaction time

For game streaming and tools like Synergy, the rule of thumb is <20ms for “smooth” and <50ms for “usable”. With AWDL on, 29% of my packets exceeded the smooth threshold. With it off, zero did.

The Scripts

All scripts are on GitHub:

• awdl-guard.sh + com.local.awdl-guard.plist - The fix (daemon + LaunchDaemon config)
• jitter-check.py - The diagnostic tool I used to find the problem. Run it against any IP to see if you have the same issue:

python3 jitter-check.py 192.168.1.1  # your router or any LAN device

If you see regular spikes every 1-2 seconds, AWDL is probably your culprit.

Conclusion

Apple’s seamless ecosystem comes at a hidden cost: AWDL constantly hijacks your Wi-Fi radio to scan for nearby devices, causing 80-90ms latency spikes multiple times per second. System Settings won’t save you - macOS re-enables AWDL after every sleep. The daemon approach is the only permanent fix I’ve found.

If you’re not using AirDrop, AirPlay, or Handoff, install the guard and enjoy your lag-free Sunshine streams, Synergy sessions, and video calls.

Tested on macOS Sequoia. Your mileage may vary on other versions.