Charles Proxy: Proxy Tool for Developers & Testers

View & Modify HTTP Requests and Responses, Throttle Network (Simulates slower internet connection) and SSL Proxying etc

Some features of Charles Proxy are:

What you’ll learn

  • Better Mobile and Web Application Testing with Charles Proxy.
  • Bandwidth Throttle / Bandwidth Simulator : Charles can be used to adjust the bandwidth and latency of your Internet connection – High Speed internet , Low Speed Internet, very low speed internet : 2G, 3G, 4G & 5G.
  • SSL Proxying : Charles can be used as a man-in-the-middle HTTPS proxy, enabling you to view in plain text the communication between web browser and SSL web server.
  • Modify HTTP Request and Response and test your application with your choice data.

Course Content

  • Setting up Charles –> 1 lecture • 6min.
  • Installation of Certifications –> 2 lectures • 6min.
  • Important Concepts : HTTP 1.1 vs HTTP vs SOCKS Proxy –> 2 lectures • 14min.
  • Setting up Simulators (iOS) –> 1 lecture • 12min.
  • Setting up Emulators (Android ) –> 2 lectures • 21min.
  • Enable Charles on Real Devices –> 2 lectures • 15min.
  • Network Throttling : Simulate 2G/3G/4G over the high-speed network like WIFI –> 1 lecture • 5min.
  • Sessions –> 1 lecture • 7min.
  • Recording –> 2 lectures • 7min.
  • Map Remote –> 1 lecture • 3min.

Charles Proxy: Proxy Tool for Developers & Testers


  • Anyone who is involved in software development or test life cycle.

Some features of Charles Proxy are:

  • Records all traffic between your browser and the Internet /  Android or iOS Mobiles and the Internet.
  • Create error scenarios by modifying APIs – mock your api responses and test various different scenarios for your dev sanity or functional testing .
  • Simulate 2G/3G/4G over the high-speed network like WIFI.
  • Reveals the contents of all requests, responses, cookies and headers
  • Supports SSL and HTTPS
  • Saves valuable time
  • Simulates slower internet connections. Yes, Charles Proxy handles this on the go. This is how you can enable handling of slower connections
  • Download statistics
  • Easily Configurable
  • Find and eliminate bugs quickly.


API reviews


Before shipping any major feature we try and do a basic API review to make sure no unnecessary API calls are being made by the app. Doing this is as easy as connecting the devices to Charles Proxy and observing and recording the API calls.


Charles Proxy is helpful in finding security bugs & loopholes. During API reviews this tool can help provide such insights:


  • Verifying if API is working properly. This means that when we do an API call, what headers are sent and is the response correct with correct headers as expected.
  • Debug if API response is incorrect.
  • Checking if any redundant API or web requests made.

For eg., We had an API to save some details on our backend. While testing the API on Charles Proxy, we came to know that the API call was being made multiple times which lead to false app behaviour. Once detected, we asked the developers to make the necessary changes.

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