https://www.macpeekapp.com/blog/ Practical guides for finding and understanding what is happening on your Mac. en https://www.macpeekapp.com/blog/how-to-find-what-is-using-a-port-on-mac/https://www.macpeekapp.com/blog/how-to-find-what-is-using-a-port-on-mac/Tue, 06 Oct 2026 00:00:00 GMTFind which process is using a port on macOS with lsof or netstat, read the output, and see the same answer from your menu bar with PortPeek. https://www.macpeekapp.com/blog/how-to-kill-a-process-on-a-port-on-mac/https://www.macpeekapp.com/blog/how-to-kill-a-process-on-a-port-on-mac/Tue, 06 Oct 2026 00:00:00 GMTKill the process using a port on macOS: find the PID with lsof, stop it with kill, escalate to kill -9 only if needed, and verify the port is free. https://www.macpeekapp.com/blog/how-to-free-port-3000-on-mac/https://www.macpeekapp.com/blog/how-to-free-port-3000-on-mac/Tue, 06 Oct 2026 00:00:00 GMTFix 'port 3000 already in use' on Mac: find the process with lsof, kill it, or use a different port. Works for Node, React, Next.js and Rails dev servers. https://www.macpeekapp.com/blog/lsof-mac-find-process-by-port/https://www.macpeekapp.com/blog/lsof-mac-find-process-by-port/Tue, 06 Oct 2026 00:00:00 GMTA practical lsof cheat sheet for macOS: find the process by port, list all listeners, filter by TCP or UDP, IPv4 or IPv6, and parse the output. https://www.macpeekapp.com/blog/mac-port-manager/https://www.macpeekapp.com/blog/mac-port-manager/Tue, 06 Oct 2026 00:00:00 GMTWhat a good Mac port manager should do: list listening ports, show the owning process, kill safely and stay private. Compare Terminal, Activity Monitor and PortPeek. https://www.macpeekapp.com/blog/mac-port-monitor/https://www.macpeekapp.com/blog/mac-port-monitor/Tue, 06 Oct 2026 00:00:00 GMTMonitor which ports are listening on your Mac in real time: with a shell loop, or with PortPeek's live-updating list in the MacPeek menu bar app. https://www.macpeekapp.com/blog/how-to-find-what-process-is-using-a-file-on-mac/https://www.macpeekapp.com/blog/how-to-find-what-process-is-using-a-file-on-mac/Tue, 06 Oct 2026 00:00:00 GMTFix 'the item is in use' and drives that won't eject: find which process has a file or folder open on macOS with lsof or Activity Monitor, and how to release it safely. https://www.macpeekapp.com/blog/how-to-check-monitor-refresh-rate-on-mac/https://www.macpeekapp.com/blog/how-to-check-monitor-refresh-rate-on-mac/Tue, 06 Oct 2026 00:00:00 GMTFind your Mac's real display resolution and refresh rate in System Settings or Terminal, and what to check when an external monitor won't run at 120 Hz. https://www.macpeekapp.com/blog/how-to-see-usb-devices-on-mac/https://www.macpeekapp.com/blog/how-to-see-usb-devices-on-mac/Tue, 06 Oct 2026 00:00:00 GMTList the USB and Thunderbolt devices connected to your Mac with System Information or Terminal, read the link speed, and spot a slow cable or port. https://www.macpeekapp.com/blog/why-wont-my-mac-go-to-sleep/https://www.macpeekapp.com/blog/why-wont-my-mac-go-to-sleep/Tue, 06 Oct 2026 00:00:00 GMTFind what is keeping your Mac awake or waking it up using pmset: read sleep assertions, check the wake log, and fix the usual causes. https://www.macpeekapp.com/blog/how-to-check-macbook-battery-health/https://www.macpeekapp.com/blog/how-to-check-macbook-battery-health/Tue, 06 Oct 2026 00:00:00 GMTCheck your MacBook's battery health, maximum capacity and cycle count in System Settings, System Information or Terminal, and what the numbers mean. https://www.macpeekapp.com/blog/how-to-check-wifi-signal-strength-on-mac/https://www.macpeekapp.com/blog/how-to-check-wifi-signal-strength-on-mac/Tue, 06 Oct 2026 00:00:00 GMTCheck your Mac's Wi-Fi signal strength, noise, channel and link speed with the Option-click menu, Wireless Diagnostics or Terminal, and how to read the numbers. https://www.macpeekapp.com/blog/how-to-find-and-kill-a-process-on-mac/https://www.macpeekapp.com/blog/how-to-find-and-kill-a-process-on-mac/Tue, 06 Oct 2026 00:00:00 GMTFind a running process on your Mac and end it safely: Activity Monitor, ps, pgrep, kill and killall, plus how ProcessPeek shows the details first. https://www.macpeekapp.com/blog/how-to-see-what-is-using-your-disk-on-mac/https://www.macpeekapp.com/blog/how-to-see-what-is-using-your-disk-on-mac/Tue, 06 Oct 2026 00:00:00 GMTFind out which process is reading and writing your Mac's disk right now with Activity Monitor and Terminal tools, and how DiskPeek shows rates per process. https://www.macpeekapp.com/blog/how-to-see-environment-variables-on-mac/https://www.macpeekapp.com/blog/how-to-see-environment-variables-on-mac/Tue, 06 Oct 2026 00:00:00 GMTList and inspect environment variables and PATH on macOS in Terminal, see why GUI apps see different values, and inspect a running process with EnvPeek. https://www.macpeekapp.com/blog/how-to-check-dns-servers-on-mac/https://www.macpeekapp.com/blog/how-to-check-dns-servers-on-mac/Tue, 06 Oct 2026 00:00:00 GMTSee which DNS servers your Mac uses and test whether each one answers, with System Settings, scutil, dig and DNSPeek. Includes how to flush the DNS cache.