How is a headless browser useful for data extraction and web scraping?
- 31/01/2023
You’ve probably heard about headless browsers if you’re working on any web data extraction projects. Perhaps you’re unsure what they are or whether you should use them.
Here, I’d want to address a few fundamental queries regarding the operation of a headless browser.
Let’s begin by examining what occurs when a web page is accessed in the context of how most scraping frameworks operate.
Web browsers
You’re probably certainly using a web browser on your computer or mobile device to read this blog. A browser is essentially a piece of software that produces a web page so that it may be viewed on a target device. It transforms the server-sent code into something that can be viewed on your computer screen, with text and images garnished with lovely fonts, pop-up windows, animations, and other pretty things. Additionally, the browser gives you the option to click, scroll, hover, and swipe in order to interact with the page’s content.
The actual rendering process, which generally entails hundreds of HTTP requests being made to the server by the browser, is really handled by your computer. To start, your browser will ask for the “raw” HTML page content. Then it will send the server a series of additional requests for extra items like stylesheets and pictures.
Websites were initially created fully using HTML and CSS. The user experience they offer now is considerably deeper and more involved. And because JavaScript displays all that gorgeous material almost instantly for viewers, modern websites frequently rely heavily on it. When a website loads slowly over a slow Internet connection, you can observe what’s happening. The page’s foundational pieces are displayed first. A few seconds later, when JavaScript does its magic, the plain-looking text is re-rendered in fancy custom fonts, and other visual frills appear.
Most websites now also provide tracking code, user analytics code, social networking code, and a variety of other things. All of this data must be downloaded before the browser can decide how to use it and render it.
Scaled Data Extraction
You want to create a scraping script to automate website data extraction. You may be asking if you need a browser for this. You’re building code to compare online marketplace goods prices. Product page HTML may not include a product’s price. The client’s JavaScript code renders it before it appears on the page.
You need automation to extract data from thousands or millions of web pages. Hiring a roomful of employees to sit in front of lots of computers and take notes is too time-consuming and expensive. Headless browsers do that. What is “headless”? The browser interacts with the target site via a graphical interface and mouse movements without human control.
You create code to tell the headless browser where to go and what to acquire from a website instead of utilizing humans. You can automatically render a page and acquire the information you need. Puppeteer, Playwright, and Selenium are popular browser interfaces. They all let you write code to visit a page, click a link, click a button, hover over an image, and capture a screenshot.
Headless Browser
Headless browsers are not used in most scraping technologies. Headless browsers are inefficient for most uses.
You wish to copy this article’s text. Browsers need hundreds of queries to display it. If you use cURL to request our URL, you’ll see this content in the initial response. Thus, you may access the text without worrying about styling, graphics, user monitoring, or social media buttons.
These things help humans use web pages. Scrapers don’t care about pretty pictures. They don’t click social media sharing buttons unless they have a bot social network, but AI isn’t that evolved yet. The scraper sees raw HTML code, which humans can’t interpret, but machines can. It’s all your program needs to find this blog post.
Using a headless browser to fetch one URL is often more efficient than rendering the complete website. Instead of requesting 100 images and stylesheets, just request the necessary information. Headless browsers are still useful.
Frequently asked questions:
What are the applications of a headless browser?
In a setting resembling that of common web browsers, headless browsers offer automatic control of a web page; however, they are run through a command-line interface or through network communication.
Why is Selenium a headless browser?
Due to items on a website that the browser needs to load, Selenium tests sometimes take a while to complete. You may drastically reduce your testing times by using headless testing, which eliminates this load time. A 30% reduction in test execution durations was observed in our headless testing experiments.
What is a headless browser, Python?
With the help of a Python headless browser, you can easily scrape dynamic content without the usage of a real browser, cutting down on the cost of scraping and speeding up your crawling procedure. When dealing with a website that needs JavaScript, web scraping using a browser-based method is helpful.
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