Cocoa Packet Analyzer

Cocoa Packet Analyzer is a native macOS utility for capturing and examining network traffic. It records packets from Ethernet or Wi‑Fi interfaces, supports promiscuous and monitor modes, and writes data to PCAP files or processes it live. The capture engine compiles BPF filters before packets reach user space, allowing tcpdump‑compatible filter expressions and a structured filter builder that validates syntax as you type.

The application presents captured data in a four‑pane document window: a recents sidebar, a sortable packet list with protocol‑specific columns, an outline view of the dissection tree, and a hex view highlighting the underlying bytes. Built‑in protocol analyzers display and filter traces, while a token‑style search field provides instant filtering, saved queries, and autocomplete for dates and protocols. Plugins can be added via Cocoa bundles to extend dissection capabilities.

Additional macOS‑focused features include QuickLook preview of PCAP files in Finder, Dark Mode support, printing, Apple notarization, and localization in English, German, and basic Japanese. The UI is fully rewritten in Swift and targets macOS 26 or later as a universal binary.