What is mDNSResponder on Mac?
By Junaid, maker of Taskglass · Last reviewed
Looks up website addresses (DNS) and finds devices like printers on your network (Bonjour).
mDNSResponder is the system's DNS resolver: every time an app needs to turn a name like apple.com into an address, mDNSResponder does the lookup and caches the answer. It also runs Bonjour, which lets your Mac discover printers, AirPlay speakers and other devices on the local network. It's essential and its activity follows your network use.
- Category
- macOS system
- Made by
- Apple
- Safe to quit:
- No
Shown in Activity Monitor as mDNSResponder, mDNSResponderHelper
Why is mDNSResponder using so much CPU or memory?
- Apps making very large numbers of network lookups (browsers, sync tools, ad blockers)
- Lots of Bonjour devices on a busy network
- VPN or DNS-filtering software changing settings
- A network problem causing lookups to retry
What to do
- 1Wait a moment; short bursts are normal when browsing or syncing
- 2Quit network-heavy apps one at a time to find the trigger
- 3Temporarily disconnect VPN or DNS filter software to compare
- 4Restart your Mac
Safe to quit? No.
Don't quit it: internet name lookups stop until macOS relaunches it.
Typical usage
Rough ranges on Apple Silicon Macs. Yours will vary.
- CPU
- 0–2%
- Memory
- 5–40 MB
Related processes
Part of the Taskglass Process Library