Charles Proxy: Proxy Tool for Developers & Testers

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.