How to capture Android traffic with Fiddler

Fiddler allows you to capture traffic logs on your Android device and utilise them for debugging network requests and responses on your Symphony mobile app.

Capture Android traffic with Fiddler by following these steps:

1. Install Fiddler on your desktop machine and ensure the PC and Android device are discoverable on the same network.

Note: Further information on installing Fiddler can be found here.

2. From Fiddler, select Tools.

3. Select Options.

4. Select the Connections tab.

5. Select the Allow remote computers to connect checkbox and ensure the value in Fiddler classiclistens onport is 8888 (Figure 1):

Figure 1 Options

6. Restart Fiddler.

Once is has been confirmed that Fiddler is listening successfully, the next step is to use it as a proxy on Android.

7. Select Settings.

8. Select Connections and navigate to WiFi.

9. On your current connected WiFi network, select the Setting cogwheel.

10. Select View More.

11. Select Proxy then Set it to Manual.

12. Enter your IP address in the Proxy host name field and enter 8888 in the Proxy port (Figure 2):

Figure 2 Settings

The setup will now allow you to capture HTTP traffic, however if you try to open any HTTPS site, you may receieve a This site’s security certificate is not trusted! error. To resolve this, you need to trust the Fiddler root certificate.

By default, the Fiddler-generated certificate is valid for a period of 5 years. However, if this causes a ERR_CERT_VALIDITY_TOO_LONG error, it can be resolved by running the about:config in Fiddler QuickExec and creating a new variable fiddler.certmaker.ValidDays with a value of 820.

You can then proceed with installing the Fiddler Root certificate by following these steps:

13. From a browser, navigate to the following URL:


14. Download the Fiddler root certificate.

15. Install the certificate on your device.

16. Confirm you can now additionally capture HTTPS traffic.

17. Once the desired requests and responses are captured, export the Fiddler log and send them to the Symphony Support team.

Note: If the files are too large to email, inform the Symphony Support team. They can arrange to receive it using a secure file transfer site, Filevault.

18. Once debugging is complete, remove the WiFi proxy from your Android device.