Packet capture library for modern Windows versions. The fast, secure, and compatible successor to WinPcap. Npcap offers: Support for Windows 10: Npcap works on Windows 7 and later by making use of the new NDIS 6 Light-Weight Filter (LWF) API. Also, the driver is signed with our EV certificate and countersigned by Microsoft, so it works even with the stricter driver signing requirements in Windows 10 1607. Extra Security: Npcap can be restricted so that only Administrators can sniff packets. We've also enabled the Windows ASLR and DEP security features and signed the driver, DLLs, and executables to prevent tampering. Loopback Packet Capture: Npcap is able to sniff loopback packets (transmissions between services on the same machine) by using the Windows Filtering Platform (WFP). After installation, Npcap will create an adapter named Npcap Loopback Adapter for you. If you are a Wireshark user, choose this adapter to capture, you will see all loopback traffic the same way as other non-loopback adapters. Try it by typing in commands like “ping 127.0.0.1” (IPv4) or “ping ::1” (IPv6). Loopback Packet Injection: Npcap is also able to send loopback packets using the Winsock Kernel (WSK) technique. Npcap does the magic of removing the packet's Ethernet header and injecting the payload into the Windows TCP/IP stack. WinPcap compatibility: For applications that don't yet make use of Npcap's advanced features, Npcap can be installed in “WinPcap Compatible Mode.” This will replace any existing WinPcap installation. If compatibility mode is not selected, Npcap can coexist alongside WinPcap.