What is Charles Proxy?

Charles Proxy sits between your app and the Internet. All networking requests and responses will be passed through Charles Proxy, so you’ll be able to inspect and even change data midstream to test how your app responds.

How does Charles Proxy work with mobile devices?


Go to Charles Proxy Download page and follow instructions to download and install it on your computer.

Configuring Charles Proxy and your mobile device

1. Configure Charles Proxy

After opening Charles Proxy go ahead and disable Windows Proxy / MacOS Proxy / Mozilla Firefox Proxy (they are enabled by default) as this will just generate extra data that is not needed when you are testing through a mobile device. Also, no need to install the Firefox plugin.

2. Get proxy port number

In the taskbar click "Proxy settings" and make a note of the proxy port number "8888".

3. Get the local IP address in the network

Click on Help > Local IP address and you'll see an IP address that is usually formatted as 192.168.x.x or 10.0.x.x

4. Add proxy server settings to your Android device

    a) Go to “Settings
    b) Go to “Wifi
    c) Long tap to a current wifi network
    d) Click the “modify network” option
    e) Click “show advanced options
    f) Under “Proxy” change to option to “Manual
    g) Set phone so all internet traffic on the mobile device runs through the PC by entering “Proxy hostname” (IP address from point 3) and “Proxy port” (8888)
    h) Click “Connect/Save

5. Install SSL certificates on your mobile device

To install Charles root certificate on Android device open https://chls.pro/ssl in your mobile browser and download the cert.

6. Collecting Logs

a) Clear the current session in Charles by clicking on the Broom Icon

b) if not currently active - Start Recording - by activating the Record icon

If the icon is red, a recording is active and calls will be captured. If you are finished with the session, you can end it from there.

You know now how to capture Charles Network logs! 👏


How to complete the Charles Proxy Test?

Open the provided URL in Native mobile web browser

For the Charles set up test use the link provided on the test page. It is specified under "Your Task" - https://platform.testlio.com/sir-charles

Once you open the listed URL, you will see a redirection page and will end up on the Testlio homepage. This means you can stop the recording. 

Stop recording 

Select File > Export Session and select Format: HTTP Archive (.har)

Upload the .har file to https://platform.testlio.com/sir-charles

Please note! During actual testing, logs will be saved as charles files. For setup confirmation, we use .har file type. 

Helpful tips

  • Clear previous logs before you start testing new functionality.

  • To install or remove certs in the iOS system, follow iGeeksBlog tutorial.

  • When all else fails, a restart of both PC and mobile device may solve issues, but make sure to Disable the Windows Proxy / MacOS proxy / Mozilla Firefox Proxy again.

  • You should periodically update your certificates as they do expire.

  • Some routers re-assign local IP addresses, so you should verify the IPv4 has not changed.

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