Choosing what to capture
Puffin only touches the traffic you ask for. Anything it does not claim keeps its normal network path.
Targeting modes
Section titled “Targeting modes”Set these in Settings ▸ Capture.
- Selected apps (the default). Only the apps you add are captured.
- All apps except the ones you exclude. Puffin adds a default exclusion list of Apple background services, and you can switch it off.
The app picker lists running apps first, then apps in /Applications, /System/Applications and ~/Applications. Apps are matched by their code-signing identifier. For a command-line tool, type its identifier by hand.
Browsers and helper processes
Section titled “Browsers and helper processes”Browsers and Electron apps often open connections from helper processes. When you choose an app, Puffin also matches helpers whose identifier extends it, such as com.google.Chrome.helper, and a small list of known aliases such as Safari’s networking process. You do not need to add the helpers yourself.
Puffin captures TCP ports 80 and 443 by default. You can add more ports in the same settings tab.
Domain lists
Section titled “Domain lists”On top of app targeting you can keep:
- an always capture list of hosts, and
- a never capture list of hosts.
Wildcards with * are allowed.
Non-HTTP traffic
Section titled “Non-HTTP traffic”If a captured connection is not HTTP, Puffin does not try to decode it. It records a tunnel entry with the host, the number of bytes and how long it lasted.
Many apps try HTTP/3 over QUIC first. QUIC runs over UDP port 443 and Puffin cannot read it. With Block QUIC on (it is on by default), Puffin refuses UDP/443 connections from the apps it captures. Those apps fall back to HTTP/2 over TCP straight away, which Puffin can read. Other apps’ UDP traffic is never touched.
Pause and stop
Section titled “Pause and stop”- Use the capture button in the main window, or the menu bar item, to start and stop capture.
- The global shortcut ⌃⌥⌘P toggles capture from anywhere.
- When capture is off, Puffin claims nothing.
- The menu bar icon shows whether Puffin is off, capturing, in an error state, or has a breakpoint waiting.
Only new connections
Section titled “Only new connections”Puffin can only claim connections opened after capture starts. After you turn capture on, or change the target apps, restart the app you are watching.
Menu bar quick switch
Section titled “Menu bar quick switch”The menu bar menu shows your current targets. Its submenu switches the mode, toggles recently added apps, and turns QUIC blocking and Simulator capture on or off.