Using Charles to Capture and Debug iOS Network Requests

Charles is a PC‑based web proxy that lets developers capture and inspect HTTP/HTTPS traffic between an iOS device and a server, greatly simplifying debugging.

Step 1 – Install Charles : Download the installer from the official website (30‑day trial) and run it on your Mac.

Step 2 – Get PC IP address : In Charles go to Help → Local IP Address or run ifconfig en1 in Terminal; note the IP.

Step 3 – Configure iPhone proxy : Settings → Wi‑Fi → (i) → Configure Proxy → Manual; enter the PC IP and port 8888 (or the port shown in Charles → Proxy → Proxy Settings).

Step 4 – Capture HTTPS traffic : Install the Charles root certificate on both Mac (Help → SSL Proxying → Install Charles Root Certificate) and iPhone (visit http://charlesproxy.com/getssl, then trust it in Settings → About → Certificate Trust Settings) and enable SSL Proxying for the desired hosts.

Step 5 – Use preview modes : Structure groups requests by domain; Sequence shows them chronologically. Switch tabs (Overview, Request, Response) and sub‑tabs (Headers, Cookies, Text) to view details.

Step 6 – Set breakpoints : Right‑click a request and choose Breakpoints to pause before the request is sent or the response is received; edit data and click Execute to continue.

Step 7 – Rewrite and modify data : Use Tools → Rewrite to create permanent request modifications, or edit request/response in Breakpoint Editing for temporary changes.

Step 8 – Repeat requests : Right‑click and choose Repeat to resend once, or Advanced Repeat to configure iterations, concurrency, and delay for simple load testing.

Step 9 – Simulate network speed : Proxy → Throttle Settings lets you emulate 2G/3G/4G conditions, adjusting bandwidth, latency, MTU, reliability, and stability to reproduce network‑related bugs.

These steps enable comprehensive inspection, modification, and performance testing of iOS network traffic using Charles.