Webscraping from client-side API

For the past few weeks, I’d been thinking about writing a short blog post explaining how to scrape information from the Internet using a website’s client-side API (when available, and when deemed legal/ethical to do so, of course).

But I kept putting it off. Then came all of the hype around chatGPT and I thought: what if this currently free, and yes completely non-sentient, large language model could generate it for me? So that’s what I’ve done.

Overall, the model did a pretty good job! Would have been nice to have some screenshots and embedded URLs to various additional sources throughout, but as anyone who has played with chatGPT knows, this is not possible.

My prompt:

Write a short 750 word instructional blog post on how to find the client-side API (.json) for purposes of web scraping using developer mode in a browser like Chrome. Tell the reader what developer mode is, explain why this is a good first step when inspecting a website before using web scraping tools that target HTML or use automated browser scraping (e.g., Selenium), and explain what the client-side API is and why it is sometimes available and sometimes not

chatGPT’s response:

Web scraping is the process of extracting data from websites. One way to access this data is through the use of client-side APIs, which are typically in the form of a .json file. In this blog, we will explain how to find and access these APIs using developer mode in a browser like Chrome.

Developer mode, also known as developer tools, is a tool that allows users to access and modify the underlying code of a website. It’s a built-in feature of web browsers such as Chrome, and it enables web developers to inspect, debug, and optimize their web pages. This can be useful for inspecting the structure and content of a website before using web scraping tools. It also allows you to access the client-side API, which can be an easier and more reliable way to extract data from a website.

To access developer mode in Chrome, you will first need to open the browser and navigate to the website you wish to scrape. Next, right-click on an element of the website (such as a button or piece of text) and select “Inspect”. This will open the developer tools window.

In the developer tools window, you will see the HTML and CSS code for the website. On the left side, you will see the HTML structure of the website, and on the right side, you will see the CSS styles. You can use this view to navigate the HTML structure and find the specific element you want to scrape.

To find the client-side API, you will need to look for the .json file in the Network tab of the developer tools window. This tab will show all of the network requests made by the website, including the .json file containing the client-side API.

Once you have located the .json file, you can click on it to see the data contained within. You can also use the “Copy as cURL” option to copy the request and use it in a scraping tool like curl or Scrapy.

It’s worth mentioning that some websites may use anti-scraping measures to prevent web scraping, such as IP blocking or CAPTCHAs. In such cases, using an automated browser scraping tool like Selenium can help you bypass these measures and access the data you need. However, using developer mode and the client-side API is a good first step when inspecting a website before using more advanced scraping tools.

Now, let’s talk about the client-side API. An API, or Application Programming Interface, is a set of rules and protocols that allows different software applications to communicate with each other. In the context of web scraping, a client-side API is an API that can be accessed directly from the client’s browser, without the need for a server-side component.

Client-side APIs are sometimes available and sometimes not. This is because, providing an API is a decision made by the website owner, and not all websites provide an API. Also, some websites may provide an API for certain functionality, but not for others.

For example, a website might provide an API for retrieving data about products, but not for retrieving data about user reviews. In such cases, you would need to use web scraping techniques to extract the data you need.

In conclusion, developer mode in Chrome is a powerful tool that allows you to inspect and access the underlying code of a website. By using developer mode, you can easily locate the client-side API in the form of a .json file, providing an efficient way to extract data from a website. This is a good first step when inspecting a website before using web scraping tools that target HTML or use automated browser scraping. However, not all websites have a client-side API available, and in these cases, other web scraping methods may need to be used.

Alex Luscombe
Alex Luscombe
PhD Candidate in Criminology