1. .
  2. Blog
  3. Web Scraping Services: How To Scrape Apps with Fiddler Everywhere

Web Scraping Services: How To Scrape Apps with Fiddler Everywhere

Does scraping apps require any specific web scraping services? Why scrape apps in the first place?
In this article we’ll be inspecting the app network traffic with Fiddler Everywhere – and scrape the data from the app servers.

web scraping services

Why Scrape Data From an App?

I usually write in this newsletter about how to extract data from websites but what if our target is an app with no web interface? Or if the website is too complex to scrape and, knowing the target has an app, we want to test if there’s another door to access the data.

Since we cannot see the source code of the app, we must intercept the requests made from it to its servers and try to replicate them in our scraper.

To do so, we need a network traffic analysis tool. In this post, we’ll use Fiddler Everywhere to support us, but there’s plenty of similar web scraping services software on the market, like Wireshark.

How Fiddler Everywhere Works

Fiddler works like a “man-in-the-middle” between your target app and its servers.

web scraping services
How Fiddler works

First of all, we need to install Fiddler on our computer and set it up to decrypt HTTPS traffic, as described on this page.

The second step is to find out the IP of our computer and configure the network on our mobile phone, where the app is installed, to use our computer as a proxy, using the port opened by Fiddler to route the network traffic.

From now on, every request made by our mobile to external servers will be shown in Fiddler. This is extremely interesting to understand what happens after the installation of a new app and to find out hidden calls to external services we are not aware of.

Start Scraping From an App: A Real Case

Going back to our web scraping services, let’s see a real-world case of how to use Fiddler.

We’ll use the app of the well-known streetwear brand Off White as an example, even if they have a website to scrape data from.

Before starting our test, let’s close all the apps on the phone in the background to reduce the noise in the requests made by our phones.

As soon as we open the app, we will see all these requests to Facebook and the Off-White internal API.

List of requests from the app

Let’s try to open a catalog page to see what happens.

I browsed to man’s ready-to-wear and, after entering the section, noticed this request.

API requests made by the app

Bingo!

There’s a web scraping API that retrieves the product information from the server.

Let’s try to replicate the same request, with the same headers, on a Scrapy project to see if it works.

I’ll start with a basic scraper, that requests only this API call, so after starting a new project in Scrapy, my spider will look like the following.

Scrapy first lines

While the settings.py file will have the variable DEFAULT_REQUEST_HEADERS set with almost all the headers we read on Fiddler.

Scrapy default headers

As you may have noticed, I’ve deleted the “Accept” and “Accept-Encoding” voices, otherwise, Scrapy would mess out with the response output format.

I’ve deleted also the Cookie parameter because I wanted to be sure that this configuration will work also in the future and not only now because we have the right Cookie assigned.

At the moment we’ll use the Bearer token read from Fiddler even if probably it won’t work in few hours, but we’ll see later how to get it dynamically.

The scraper should print the resulting JSON on the terminal.

Scrapy results

It works!

Now let’s define the Item properties and fields and read the JSON. I suggest copying the whole JSON output into any online formatter tool, like https://jsonformatter.curiousconcept.com/, it helps a lot to understand its structure.

Item class declared in Scrapy
JSON formatted result

Let’s use the JSON structure to assign fields to Item fields, the scraper will run like the following.

Scrapy first 60 results

60 items scraped, perfect, the same number as the items in the JSON!

***

This article was kindly provided by Pierluigi Vinciguerra, web scraping expert and founder of Web Scraping Club. Follow this link to see the original post.

Download GoLogin here and explore the scraping world with our free plan!

Also read

Integration of proxy services

How to GoLogin integration?

Browser automation with Selenium

There are many kinds of tasks for a browser profile. Any tasks can be automated using Browser automation.

web scraping

Web Scraping 101: Tools, Techniques and Best Practices

What is web scraping? Do people actually earn with that? What are best tools and tricks to scrape for data? See it all in our complete guide!

We’d love to hear questions, comments and suggestions from you. Contact us [email protected] or leave a comment below.

Are you just starting out with GoLogin? Forget about account suspension or termination. Choose any wed platform and manage multiple accounts easily. Click here to start using all GoLogin features