Daniel - November 26, 2019
What is Headless Browser? Is Headless Browser Good for Web Scraping?
In this tutorial, we will show you what exactly an headless browser is and why it is good for web scraping.
A headless browser is a name given to a browser without the identifiable user interface that differentiates it from other standard web browsers.
It might please you to know that headless browsers are like any other real browsers you are familiar with such as Google Chrome, Opera, Safari, Mozilla Firefox, etc. but with a blank page. There are no buttons or tab to click on; all you see is an empty page.
Headless browsers became more popular due to the increasing rate at which web development is evolving. Besides, headless browsers interact only with your written JavaScript.
Developers are continually improving on ways to build highly responsive and interactive websites with an optimized user interface that will give every visitor a fantastic experience navigating such sites.
Google’s revelation about the usefulness of headless browsers in giving websites high indexing in Google’s search result index is a crucial factor that has led to the rapid development of headless browsers.
Google needs only your basic HTML file with all its contents in place for its search result ranking. The headless browser makes this possible by executing your JavaScript and also filling in your web content for Google-bot to read.
What is a Headless Browser?
As mentioned earlier, headless browsers function like all other browsers with all other components like the networking component, Javascript interpreter, rendering, and layout engines in place but without a graphical user interface (GUI).
Developers find headless browsers useful for testing websites, web apps, as well as mobile apps without the need for an interface.
Nevertheless, users can navigate on headless browsers using the browser’s API (command-line interface) or a computer console. Therefore, a developer can automate testing process, extract web content for other uses, take screenshots of a rendered JavaScript, etc.
Before choosing a headless browser solution for web development, you should consider the weight of the headless browser. A lightweight headless browser uses minimal resources and also runs efficiently in the background while working, causing a lag.
Asides choosing a lightweight headless browser, you should be able to use such a browser to carryout necessary simulation tests for conceived users’ actions.
However, not all headless browsers are well suited for various simulation tests. Hence you may have to try out several options to discover the right combination of headless browser solutions for your developmental needs.
Common examples of headless browsers include Phantom JS, Google Chrome version 59, or other higher versions, Mozilla Firefox v56, HtmlUnit, Trifle JS, SlimerJS, etc.
Advantages of headless browser
Automating web development processes
Headless browsers save you time and energy by automating the development, quality, and testing phases of a website, mobile app, or web app development.
Faster performance
Headless browsers perform up to fifteen times faster than a real browser. Besides, the headless browser does not need to load CSS and JavaScript. It does not need to open and render HTML as standard web browsers do.
Web scraping functionality
Web scraping with a headless browser is possible because you don’t need to launch a website manually before scraping, you can go straight up and scrape the website’s HTML with a headless browser.
Monitor performance of automated processes
You can use a headless browser to monitor the performance of network applications. You can also use it to automate the rendering and capturing of website images for automated layout checks.
Disadvantages of headless browser
A headless browser does not give you a real user experience like a regular browser would do.
Debugging headless browsers is quite tricky because Headless browsers cannot identify cosmetic bugs related to a button’s location, color display, etc.
Headless browsers are also used for DDOS (distributed denial of service) and brute force attacks. In some instances, headless browsers are used to boost ad revenue generation by faking user interaction and page loads
The speed of headless browsers is significantly low. In some cases, when you have to run many tests.
What are the use cases of headless browsers?
A headless browser is an invaluable tool in the hands of a developer. A headless browser is useful for the following functions
For automating web browser tasks in web-based apps. You can use a headless browser to automate tasks, scripts, and UI tests without the need for a standard browser.
For scraping data from websites Using a headless browser, you can navigate and scrape data quickly: and effortlessly from a website. You do not have to launch a website before scraping data from such sites.
For testing layouts: You use headless browsers to test web properties like a web page layout, font types, color selection, etc. Testing for a page layout tests includes determining a web page’ default dimensions, co-ordinates determination, etc.
For taking screenshots and generating PDFs of webpages asides taking screenshots, you can also use it for JavaScript and AJAX execution testing.
You can use a headless browser to automate website interaction
You can use a headless browser to run tests on systems lacking a GUI
A headless browser is also used for monitoring the performance of network applications
You can use a headless browser to capture a website’s timeline trace for executing performance diagnosis
You can also use headless browsers to automate website interaction to simulate multiple browsers on a single system without making use of resource hog.
Is a headless browser faster than real web browsers?
What makes headless browsers 15 times faster than real browsers is that a headless browser does not have to render HTML, CSS, JavaScript, and images. Also, a headless browser does not have to wait for the page to complete loading before carrying out its functions.
Google Chrome and Mozilla Firefox are equally as fast as headless browsers because both browser developers invest a lot of time and energy to make both browsers and JavaScript engines superfast both for regular use and automating web browser tasks.
The Graphics user interface in a real browser gives users a fantastic user experience (UI) browsing but makes it heavier to load.
Hence, normal browsers execute automated tasks at a much slower pace because of the resource-intensive nature of a Graphics User Interface (GUI)
You can use Google Chrome versions 59 or higher versions and Mozilla Firefox version 56 or higher version to perform functionalities related to the headless browsers.
Developers can now enjoy a fantastic performance speed using the headless versions of Google Chrome and Mozilla Firefox.
However, scaling real browsers in a test execution using a Continuous Integration (CI) environment is quite tricky. Because running such tests on Continuous Integration servers requires extra configuration settings as a display server, unlike using a headless browser solution that does not require additional CI configurations.
Examples of Headless Browser Software Solutions
As a developer, it is pertinent for you to try out various types of headless browsers to enable you to get the perfect combination of headless browsers suitable for automating web browser tasks and other developmental processes.
Therefore, we will be exploring some commonly used headless browser solution.
1. Google Chrome Headless Browser (version 59 of Google Chrome)
Google Chrome headless browser is a lightweight headless browser based on the Open source Google Chromium project. It has a BSD license and supports JavaScript language.
Developers use headless Chrome for the following functions:
For multiple levels of navigation testing: It is essential to test navigations on various levels due to the increasing use of smartphones to access websites. Therefore, testing navigation on headless Chrome ensures visitors on mobile or desktop platforms enjoy accessible navigation.
Scraping data from websites. You can use the headless Chrome to collect data and images on the performance of a website that can then be used for improving a website’s User Interface.
For taking screenshots of webpages
For creating PDF versions of webpages.
2. Mozilla Firefox Headless Browser (V.56)
The headless version of Mozilla Firefox allows developers to run several APIs smoothly without having to combine several simulation tools for web development tests.
However, using the headless version of Mozilla Firefox works well for web browser automation tests by combining any of the below headless drivers for maximal functionalities.
Selenium: Selenium is a preferred choice of API for driving testing and automation processes in the headless version of Mozilla Firefox.
Slimmer JS
W3C WebDriver
3. Phantom JS WebKit
Phantom Js headless browser uses the command-line interface to handle several types of complexities in web browser automation tests and processes.
Although Phantom JS is unmaintained, it is an open-source scriptable WebKit that runs on JavaScript, PHP, Python, Java, Ruby, Haskell, C#, Perl, Objective-C, and R APIs using the BSD and 3-Clause licenses.
Phantom JS offers fast and native support for web development processes like DOM handling, JSON, SVG, Canvas, and CSS selectors.
Developers often use Phantom JS for the following purpose:
Multi-levels Navigation testing
For behavioural simulation
Taking screenshots of webpages.
Working with various assertion types
4. HTML Unit
HTML unit is a headless browser solution written in Java. It is mainly used to automate website interaction with users.
On the other hand, HTML Unit can simulate different types of browsers like Chrome, Edge, IE8 &11, Firefox version 38 and above, etc. ensuring that users get a fantastic User Experience (UX) once the developer launches the site.
HTML Unit is also used for building and simulating e-commerce website elements like site security, form submission, navigation, etc.
Developers also use the HTML Unit to enhance the user experience by making a website’s Graphic User Interface more interactive. Hence, the HTML Unit is a popular tool for developing interactive websites with satisfactory performance.
Other uses of the HTML Unit
Form filling and submission processes
Links Redirection to other websites
Authenticating HTTP
HTTPS page performance
HTTP header performance
5. Splash Headless Browser
The Splash headless browser is also a lightweight browser with several useful features. Splash headless browser renders JavaScript service using HTTP API implemented in Python using ‘Twisted’ and QT5. It supports all Languages and also has a BSD and 3-Clause license.
Using the Splash tool, you can render information in HAR format, take screenshots of webpages, and also integrate it with Scrapy for web scraping functionalities.
Splash is a useful headless browser solution with multiple functionalities that makes it a much-desired tool by developers.
Splash is best for
Simulating and understanding the Performance of HTML
Load speed and rendering tests
Web browser automation
Testing Ad Blockers for a faster website loading experience
Simulating User Experience on websites.
It makes it easy Working on several webpages at a time.
Is Web Scraping using Headless Browser Possible?
Headless browsers have web scraping functionalities for scraping data from websites. To perform web scraping functionalities, it essential to use a rotating proxy to evade modern anti-scraping technologies employed by most websites.
With ProxyRack services, you are provided with access to over 2 million rotating proxies to mask and change your IP address at regular intervals (hence the term rotating proxy).
Besides, rotating proxies prevent websites with anti-scraping technologies from blocking your IP address due to consistent requests made to the servers.
Headless browsers are well-suited for scraping data from websites because of their flexibility and highly optimized performance.
Why you should use Rotating Proxies with a Headless Browser for Web Scraping?
Using a proxy server with a headless browser to scrape enables you to scrape data from websites anonymously without the website’s server blocking your IP address.
A rotating proxy enables you to access and scrape data from websites with geo-restricted contents. This is very important for scraping product data from e-commerce platforms like Amazon, Shopify, etc. because products from such specific locations are displayed with the use of a ProxyRack Rotating proxy IP.
You can make a considerable volume of data requests using ProxyRack Rotating IP addresses without fear of getting banned.
You can run several sessions on a website using ProxyRack Rotating IP addresses.
You can use a rotating proxy to bypass blanket IP bans designed to block a large volume of data requests.
Bottom Line
An essential factor to take into consideration when scraping data is the ability to scrape data anonymously without hassles.
It is worthy of note to use a rotating proxy service compatible with your web scraping tool for seamless data scraping experience.
ProxyRack is compatible with all commonly-used web scraper tools. It also offers you all-round anonymity with its rotating proxy feature which changes your IP address automatically following an automated schedule IP changing, or manually.
Lastly, ProxyRack is just the perfect combination of tools you need to evade anti-scraping technologies of websites while enjoying an optimized web scraping experience with any of the aforementioned headless browsers.
