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What Is Web Scraping - Basics & Practical Uses

Monday, January 24, 2022

A basic intro to lead you in the world of web scraping. What is web scraping? How does it work, how is it used? What are the pros and cons? All questions that concern you will be answered here.




What is web scraping?

Web scraping is a way to download data from web pages. 


You may have heard some of its nicknames like data scraping, data extraction, or web crawling. (web crawling could be narrower and refer to data scraping done by search engine bots) In most cases, they refer to the same meaning - a programmatic way to pull data from the web.


Web scraping helps fetch data (like emails, phone numbers, articles, etc.) from web pages and organize it into certain formats like Excel, CSV or HTML, etc.



See how Wikipedia explains web scraping:


“The content of a page may be parsed, searched, reformatted, its data copied into a spreadsheet or loaded into a database. Web scrapers typically take something out of a page, to make use of it for another purpose somewhere else. An example would be to find and copy names and telephone numbers, or companies and their URLs, or e-mail addresses to a list (contact scraping).”


In essence, web scraping is a dedicated data collector who captures the exact set of data you want from a load of web pages and makes it into a neat file for your download and further use.



Read the article in infographics



What's the point of web scraping?

Big Data and Automation are no longer new concepts in the current business world. They are widely used techniques to improve people’s effectiveness and efficiency.


Big data is big for the amount. Automation is about getting things done on autopilot. And web scraping is good at both - getting voluminous data fast with little human labor required.


In the context of big data collection, web scraping is the rescue. If you want to train a machine learning model, a great amount of accurate input data will make you smile. This data will teach your model important lessons and get you a more intelligent algorithm. 


That’s when web scraping plays the ace - to grab you data efficiently from a number of websites and get it into a machine-readable format for quick use.


Well, not everyone has an AI model to train, but most of us need to collect data for different purposes. Web scraping’s nature of automation extremely improves people’s working efficiency and eliminates human errors. Lay back and let the robot do what is repetitive.

When you get to the use cases#, you will find out how web scraping helps in real cases.


How does web scraping work? 

Web pages’ data is written in the HTML file. Browsers like Chrome and Firefox are tools that read the HTML file to us. 


Therefore, no matter how diverse web pages are presented to us, every string of data we see in the browser is already written in the HTML source code. Whatever you see can be traced and located in the code (by Xpath, a language used to locate an element). 


Web scraping finds the right data according to where it locates and takes a series of actions (such as extract the selected text, extract the hyperlink, input a preset data and click certain buttons, etc.) just like a human, except that it surfs the Internet, copy the data fast around the clock and feels no fatigue. 


Once the data is ready, you will be able to download it from the cloud or to the local file for any further use. 


How is web scraping used?

Who is doing web scraping and how do they get empowered by web scraping? Here are some use cases. You may discover how web scraping could benefit yourself as well.


Who is using web scraping?

Web scraping is widely used in industries like:

  • jobs & recruitment
  • consultancy
  • hotel & travel
  • eCommerce & retailing
  • finance and more
  • marketing


Tips: Check how to get started#, an example of how I started to build my web scraper and got data from Youtube that helped my KOL marketing.


They are getting data mostly for price/brand monitoring, price comparison, and big data analysis that serve their decision-making process and business strategy.


For individuals, web scraping helps professionals like:

  • data scientists
  • data journalists
  • marketers
  • academic researchers
  • business analysts
  • eCommerce sellers and more 

(to obtain data that support their sales, marketing, research, and analysis.)


Does web scraping sound like a big undertaking to you? Believe me, it is not. It can be used in many trivial ways and help you out of tedious, repetitive work. Basically, if you need data that could be found in websites and you don’t want to do mind-numbing copies and pastes manually, you use web scraping.


Read also:



What are the most scraped data/websites?

According to the Most Scraped Websites by Octoparse, eCommerce marketplaces, directory websites and social media platforms are the most scraped websites in general. 


Websites like Amazon, eBay, Walmart, Yelp, Yellowpages, Craigslist, social media platforms like Facebook, Twitter and LinkedIn are among the popular.


What data are people getting from these sites? Well, everything that serves their research or sales. 

  • Online product details like stock, prices, reviews and specifications; 
  • Business/leads information like stores’ or individuals’ name, email, address, phone number and other information that serve any outbound gestures;
  • Discussions on the social media or comments on the review pages that offer data sources for NLP or sentiment analysis. 


The need of migrating data is also one of the reasons people choose web scraping. A scraper then works out like a grand CTRL+C action and helps copy data from one place to another for the user. 


You may be interested in web scraping business ideas to discover more detailed information about how web scraping is used in practical scenarios.



The Pros and Cons of Web Scraping

Because of its accuracy and efficiency, web scraping empowers individuals and businesses in many ways. However, worries always exist - will it be too complicated to handle? Is it hard to fix and maintain, etc. Well, fair questions. While if you got the opportunity to dive into it, you will see the advantages of web scraping very likely outweigh what means to you the tricky part.


The advantages of web scraping

#High speed

Getting data faster. This is self-evident and may be the core reason people resort to web scraping. Compared to manually doing this, a web scraper can execute your commands automatically, according to the workflow you have built for it. Each step of work that would have taken up your time will be done by the scraper. 


Once you set it up, it will run for you relentlessly, getting all kinds of web data fast from different websites. If you wanna try how fast a scraper can be, I recommend you to try our scraper templates. You may try an Amazon scraper to gather product details or product reviews and see how a scraper can get you hundreds of well structured data lines in just a minute.


Download Octoparse to witness the speed of web scraping.


BTW, web scraping is a valuable tool to study market trends and gaps, voice of your customers and gestures of your competitors since it helps grab this data fast and easy from all different sources.


“Time is money!”

——Benjamin Franklin



Web scraping is widely accepted by not only big companies but also SMBs. It just saves money.


First of all, hiring a development team would cost a lot. Looking for the right talents, dealing with leadership and management stuff to put them together and work effectively, human resources issues, all of these are time-consuming (and sometimes psyche-consuming). 


Web scraping takes repetitive work without the need of a coffee break. Unless you have a long-term development plan to carry out (or you got a big budget to squander), web scraping is worth a try.


The returns of setting up a scraper (or a set of scrapers) can be considerable. 


For example, if you want a series of product prices information and get it updated daily for a year, you may spend a few days or even weeks to configure the scrapers, test and fine-tune it. Once it is well built, it can work for you as long as you need it. Fresh price data will be delivered to you every morning then, more punctual than the employees in your office. 


Well it is not a once-for-all work. You may spend some time maintaining the scraper# now and then, but it saves you a grand number compared to the cost of data delivery for 365 sets of price data a year.


#Compatibility and flexibility

The flexibility of web scraping enables you to get data exactly in the form of how you need it. For example, regular expression is one of the ways to get your data cleaned. You can set commands with regex to refine the strings of data by adding a prefix, replacing A by B, cutting certain bytes of data, etc. 


If you are scraping San Francisco local business phone numbers from Yelp to import it into your tele-marketing system, while your system recognizes only local numbers without the area code, Regex can help you eliminate the string “(415)” of every number. Data can be cleaned as the scraper processes.


File formats also make things easier. Octoparse scrape web data and export it into different formats like EXCEL, CSV, HTML and JSON. These files are compatible with most apps and systems of data management, data analysis and visualization. 


An Octoparse user once told us that he is running a price comparison website. He set the tasks to run daily so that the prices are fresh. And the data scraped is automatically exported to his database which connects to his website. 


A web scraper can be a data pipeline that extracts data from the web, clean it, organize it into the right format, copy it to your database and which could be then uploaded to your websites/systems. You can’t imagine how an individual could run and maintain a website by himself, getting the data on it refreshed everyday without web scraping.  


That’s how web scraping can perfectly fit into your workflow and extremely improve productivity. 


#Capacity to get data that API can’t

API is short for Application Programming Interface. An API gives people access to the data of an application or system which is granted by the owner.


According to Wikipedia:

“An API is a connection between computers or between computer programs. It is a type of software interface, offering a service to other pieces of software. One purpose of APIs is to hide the internal details of how a system works, exposing only those parts a programmer will find useful and keeping them consistent even if the internal details later change.”


Hence what data you can get through API highly depends on which part of the information is open to the public. In most cases, applications and services would offer only limited access to the public free of charge or sometimes at a cost.


And the specification to build an API connection varies from apps to apps. If you are looking for data from only one or a few sources, and luckily the data you need is all granted, you can study the API specification and take advantage of it. Honestly, to maintain an API connection could be easier to maintain a web scraper.


While a web scraping tool can become a data console where you gather data from different websites with a series of scrapers and become a data pipeline when you connect the tool to your database. And a web scraper can ignore the limit of API and extract what data you can see on the browser. Therefore, web scraping is more customizable, and when you need data from multiple sources, more powerful as an aggregator.


The disadvantages of web scraping

Web scraping is powerful, while you may have heard of some of its’ limits and wonder if you are able to deal with them. For example, during the scraping we can get blocked by the target websites. In this section, we will have a closer look at them.


Tips: If you want to know more possible obstacles, in this article 9 web scraping challenges are discussed. Octoparse has its customizable solutions to different situations. If you are stuck in any one of these issues and wonder if Octoparse can be your alternative solution, feel free to contact us at support@octoparse.com. Our colleagues are happy to help.


#Start with a learning curve

Web scraping tasks can be a lot easier with a no-code web scraping tool like Octoparse since a non-coder does not have to learn python, R or PHP from scratch and can take advantage of the intuitive UI and the guide panel. 


However, even a web scraping tool takes time to get familiar with because you have to understand the basic idea of how a web scraper works so that you can command the tool to help you build the scraper.


For example, you shall know how the data is weaved into a HTML file with different HTML tags and structures. You may learn the basics of Xpath to locate the data you need. This is also what I learn (and more) throughout my journey with Octoparse.


#Your IP may be blocked

Web scraping is about frequently visiting a website or a set of web pages, sometimes clicking and sending many requests in a short period of time (so as to capture the required data on the pages). Because of the abnormal frequency, your device or IP may be detected as a suspicious robot that is executing malicious attacks to the service.


IP blocking is likely to happen when you scrape websites that are protected with strict anti-scraping techniques such as LinkedIn and Facebook. The tracking and detection is mainly based on the IP footprint. Therefore, IP rotation or using IP proxies is an important technique for anti-blocking.


This is inevitable due to the speed of web scraping, while solutions like IP proxies and Cloud services offer a way out.


#Web scraper requires maintenance

The scraper is built to grab data according to the HTML structure. If the website you are scraping has changed its structure, for example the data you need is moving from place A to place B, you then have to amend your scraper to adjust to the change.


We have no control over the external website, hence only to keep up with it. As long as you get a hang of a web scraping tool, and become familiar with the anti-scraping tricks, it would be easier for you to react to these changes.


How to Get Started?

There are a lot of crash courses on platforms like Youtube and Medium to teach people how to start learning web scraping with python. Honestly, this is not what I am good at. As a total newbie in programming, I started with a no-code, or low-code method. It’s good because I still got the data I wanted.


No-code: A Web Scraping Tool 

I wanted to scrape Youtube KOL channel data for marketing purposes. I could not write a line of code (now I have learned some HTML basics). It doesn’t matter - I work in Octoparse. Aha.


So I picked the software up and for two weeks I learned the basics of HTML and Xpath, and got familiar with the software as I haven’t really used it for long. I started to build my own scrapers. You may be interested in the story of how a marketer made use of a no-code web scraping in work.


If you are looking for a way to get data with web scraping and want to start easy, a no-code tool would be a nice pick even though you are new to it (you can’t be more new to a programming language). 


Ask yourself two questions before downloading a web scraping tool:

  • What data are you looking for?
  • Where to obtain it?


When you have the answers, you will get a list of web pages and the exact data you need to download from them in mind. Next step, you can enter the URL into Octoparse and start point and click at the built-in browser and build yourself a web scraper.


Tips: Need to scrape some data from the web and not sure if it is feasible with the web scraping tool? Feel free to consult us through support@octoparse.com.


I planned to make a checklist of what you shall learn before building yourself a web scraper but it reminded me that I got the basics of HTML and Xpath along the way when I built scrapers with Octoparse through trial and error.


So if you have a web page URL and the target data you want to pull down, just download Octoparse and play with it.


Who is Octoparse?



And here are some resources you may need along the way as you get onboard:

> Tutorials to get started

> Youtube videos: Web scraping cases

> Onboarding webinar


Tips: Basically, you need to understand:

1) The workflow of a web scraper (so that in the same logic you will be able to build one)

2) The basics of HTML and Xpath that helps you locate exactly the data you need to scrape.


And you will be ready to start! 


Author: Cici 

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