Choose Advanced IP Scanner if…
You want to find Windows machines and get straight into them: it opens RDP and Radmin sessions and network shares from the results, can switch computers on and off remotely, and runs as a portable app with no install. It is free and made by Famatech.
Choose Angry IP Scanner if…
You need a scanner on macOS or Linux as well as Windows, want open-source software, or want to extend results with plugins and custom openers. It pings each address, then optionally resolves hostnames, finds MAC addresses, scans ports and reads NetBIOS information.
Choose Packet Echo if…
You are troubleshooting or documenting a network rather than administering the PCs on it. The free edition adds what a scan alone cannot tell you: which switch and port this machine is on (LLDP and CDP), an ordered Diagnose check of link, internet path, DNS and throughput, services announced over SSDP and mDNS, Wi-Fi details, and rogue DHCP detection. Pro adds a read-only SNMP switch view, topology maps, packet capture analysis and branded client reports, for $79 once with every future update included.
Using more than one
They do not conflict. Plenty of technicians keep a remote-access scanner for the help desk and a diagnostic tool for site visits.