In this step by step tutorial, learn how to setup your Аndroid device to use Fiddler as a proxy and capture web traffic from your phone.
Debugging web applications on Windows is fairly easy. Every browser has its own developer tools, and most importantly you can use Fiddler. However, this is not the case if you’re mobile developer that want to debug an application or website from Android device. Luckily, you can still use Fiddler to do it.
First you have to have Fiddler installed on your desktop machine. The PC and the Android device should be discoverable on the same network. This was the tricky part for me, as even when I have them on the same network, they couldn’t communicate with each other. I had to use the mobile hotspot on my machine to make them discoverable.
Just ping the device IP from your machine to be sure they can communicate.
First, you should enable the Allow remote computers to connect setting in Fiddler
Fiddler is now listening on port 8888 (this is the default port, you can change it from the setting above).
Once Fiddler is listening, we should use it as a proxy in Android.
Your device’s traffic should be visible in Fiddler.
With the current setup you should be able to capture HTTP traffic. However, if you try to open any HTTPS website, you’ll get the This site’s security certificate is not trusted! error. To fix this, you should trust the Fiddler root certificate.
NOTE: By default, Fiddler-generated certificate is valid for 5 years. However, this can cause ERR_CERT_VALIDITY_TOO_LONG error in Chrome on Android. To fix this:
Then, you can proceed with installing the Fiddler Root certificate as follow:
Now you should be able to capture HTTPS traffic too.
Once you’re done debugging, don’t forget to remove the WiFi proxy from your device.
This is all you need to know about capturing web traffic from Android devices with Fiddler. If you have any questions or problems, just leave a comment below.
We always love hearing feedback, so feel free to share your thoughts on what you'd like to see with us over on our Feedback Portal. And if you're new to Fiddler, you can get started today - download Fiddler for free right here.
Kamen is software developer and manager of the Fiddler team at Progress. He has more than 11 years of professional experience in software development. Programming has always been his passion and he feels lucky to work his hobby. In his free time, he enjoys traveling, motorcycling, freshly-roasted coffee, and trying new experiences. Geek by design. Writing is a new thing to him and he’ll appreciate your feedback and comments.
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