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Introduction to Web Scraping. How it Works? What are Tools and Categories?

Updated: Mar 10, 2022

Web scraping is an automatic method to obtain large amounts of data from websites. Most of this data is unstructured data in an HTML format which is then converted into structured data in a spreadsheet or a database so that it can be used in various applications. There are many different ways to perform web scraping to obtain data from websites. These include using online services, particular API’s or even creating your code for web scraping from scratch. Many large websites, like Google, Twitter, Facebook, Stack Overflow, etc. have API’s that allow you to access their data in a structured format. This is the best option, but there are other sites that don’t allow users to access large amounts of data in a structured form or they are simply not that technologically advanced. In that situation, it’s best to use Web Scraping to scrape the website for data.


Web scraping requires two parts, namely the crawler and the scraper. The crawler is an artificial intelligence algorithm that browses the web to search for the particular data required by following the links across the internet. The scraper, on the other hand, is a specific tool created to extract data from the website. The design of the scraper can vary greatly according to the complexity and scope of the project so that it can quickly and accurately extract the data.


How it Works:

To grasp web scraping, it’s important to first understand that web pages are built with text-based mark-up languages – the most common being HTML.


A mark-up language defines the structure of a website’s content. Since there are universal components and tags of mark-up languages, this makes it much easier for web scrapers to pull the information it needs.

Parsing through HTML is only one-half of web scraping. After that, the scraper then extracts the necessary data and stores it. Below is a visualization of what the work of a web scraper may look like:



Web scrapers are similar to application programming interfaces, or APIs, which allow two applications to interact with one another to access data.


There are a few ways to scrape the web today.

  • One can hire a developer with experience in data extraction to write a bot (or web crawler) to find the information they need. These developers are fairly easy to locate on freelance platforms with the right search.

  • A project of large scale, or for those with limited coding experience, could benefit greatly from the use of web scraping tools. These tools are more niche, but you can find them in our “other analytics software” category.



Web Scraping Tools

Based on how they work, the following is a classification of web scraping tools available in the market:


1. Browser Extension

Browser extension is a great tool if you want to scrape small portions of data. If you want to browse and scrape data through your browser plug-in rather than separate software installed on your PC, this is the best tool to opt for! You can install the extension and choose the way you want to scrape the data from a website of your choice. The data will download in CSV or any other downloadable format. Easy as it is, it has its limitations too! It can scrape only one page at a time. So if you are looking for a tool for large amount of data, browser extension is not your best bet!


However, if you want to scrape small parts of a website, browser extension is a great tool. So install the browser plug-in and keep scraping the data the way you want!


2. Installable Software

As the demand for data is growing manifold, several companies have come up with installable software of every kind. Like any other software, you will need to install web scraping software on you PC. No need to worry whether it would compatible with your PC. Most of the software are Windows-based. All you need to do is configure the software.

Wondering about the format of the data? It will be available in CSV or any other downloadable format.

Software suits you best if you want to scrape small to medium chunks of data. Unlike a browser extension, you can scrape one or more pages at a time.


3. Cloud Based

Compared to other tools, Cloud Based web scraping is considered to be the most robust solution!

There’s no hassle of installation of software on your PC. All you need to do is configure your plan and requirement. That’s all! Once you do this, you can get your data through API and downloadable format!

If you want to scrape large amount of data and don’t want to be worried what will happen if you scrape large amount of data, this is your most reliable solution. The reason why there is no upper cap on the amount of data to be extracted is because it runs on multiple computing environment.


Compared to other tools which require ‘start-stop’ intervention in a manual way, Cloud-based service can liberate you from all of this and render web scraping a completely hassle-free experience.


Types of Web Scrapping

Web scrapers can drastically differ from each other on a case-by-case basis.

  • self-built or pre-built

  • browser extension vs software

  • User interface

  • Cloud vs Local


Self-built or Pre-built

Just like how anyone can build a website, anyone can build their own web scraper.

However, the tools available to build your own web scraper still require some advanced programming knowledge. The scope of this knowledge also increases with the number of features you’d like your scraper to have.

On the other hand, there are numerous pre-built web scrapers that you can download and run right away. Some of these will also have advanced options added such as scrape scheduling, JSON and Google Sheets exports and more.


Browser extension vs Software

In general terms, web scrapers come in two forms:

  • browser extensions or

  • computer software.

Browser extensions are app-like programs that can be added to your browsers such as Google Chrome or Firefox. Some popular browser extensions include themes, ad blockers, messaging extensions and more.

Web scraping extensions have the benefit of being simpler to run and being integrated right into your browser. However, these extensions are usually limited by living in your browser. Meaning that any advanced features that would have to occur outside of the browser would be impossible to implement. For example, IP Rotations would not be possible in this kind of extension.


In Computer Software, you will have actual web scraping software that can be downloaded and installed on your computer. While these are a bit less convenient than browser extensions, they make up for it in advanced features that are not limited by what your browser can and cannot do.


User Interface

The user interface between web scrapers can vary quite extremely. For example, some web scraping tools will run with a minimal UI and a command line. Some users might find this unintuitive or confusing.

On the other hand, some web scrapers will have a full-fledged UI where the website is fully rendered for the user to just click on the data they want to scrape. These web scrapers are usually easier to work with for most people with limited technical knowledge.


Some scrapers will go as far as integrating help tips and suggestions through their UI to make sure the user understands each feature that the software offers.


Cloud vs Local

Local web scrapers will run on your computer using its resources and internet connection. This means that if your web scraper has a high usage of CPU or RAM, your computer might become quite slow while your scrape runs. With long scraping tasks, this could put your computer out of commission for hours. Additionally, if your scraper is set to run on a large number of URLs (such as product pages), it can have an impact on your ISP’s data caps.


Cloud-based web scrapers run on an off-site server which is usually provided by the company that developed the scraper itself. This means that your computer’s resources are freed up while your scraper runs and gathers data. You can then work on other tasks and be notified later once your scrape is ready to be exported.


This also allows for very easy integration of advanced features such as IP rotation, which can prevent your scraper from getting blocked from major websites due to their scraping activity.



Usage:

Web Scraping has multiple applications across various industries. Let’s check out some of these now!


1. Price Monitoring

Web Scraping can be used by companies to scrap the product data for their products and competing products as well to see how it impacts their pricing strategies. Companies can use this data to fix the optimal pricing for their products so that they can obtain maximum revenue.


2. Market Research

Web scraping can be used for market research by companies. High-quality web scraped data obtained in large volumes can be very helpful for companies in analyzing consumer trends and understanding which direction the company should move in the future.


3. News Monitoring

Web scraping news sites can provide detailed reports on the current news to a company. This is even more essential for companies that are frequently in the news or that depend on daily news for their day-to-day functioning. After all, news reports can make or break a company in a single day!


4. Sentiment Analysis

If companies want to understand the general sentiment for their products among their consumers, then Sentiment Analysis is a must. Companies can use web scraping to collect data from social media websites such as Facebook and Twitter as to what the general sentiment about their products is. This will help them in creating products that people desire and moving ahead of their competition.


5. Email Marketing

Companies can also use Web scraping for email marketing. They can collect Email ID’s from various sites using web scraping and then send bulk promotional and marketing Emails to all the people owning these Email ID’s.

Web Scrapping Advantages and Disadvantages:


Advantages:

Some of the primary yet significant benefits that have made this technique so popular among different communities and industries are as follows;


1. Data Management Accuracy

With the introduction of web scraping, the accuracy of data extraction was also introduced. As we all know, human error is always a factor when performing a task manually, leading to more significant issues in later stages. Especially in finance industries where sales and cost prices are concerned, accuracy plays a vital role, and here, this technique comes in handy. Therefore, web crawling allows not only automated and comfortable but also accurate data mining.


2. Economical

Manual data extraction is an expensive task to perform as it requires a considerable workforce and massive budgets. Still, just like many other activities, web scraping has resolved this issue as well. Data mining is cheaper than ever before because it has to be collected and analyzed back from the main websites for the internet to function regularly.


3. Easy Implementation

Web scraping with proper deployment of the scraping mechanism requires one-time investment and retrieves massive data from not the entire domain.


4. Management of Data

Web scraping allows a person to download and manage data onto his local computer in spreadsheets or databases, which cannot be done on configured HTML websites. Moreover, this technique has removed the idea of copy and pasting, as it engulfs most of the time that can be utilized in many other creative things.


5. Low Maintenance and Speed

Web scraping is a budget-friendly technique as it requires significantly less or no maintenance over a long period that saves the maintenance cost. Apart from this, it helps scrape the data in a few hours that used to be done manually in days or weeks.


Disadvantages:

Some of the disadvantages of web scraping are as follows;


1. Difficulty in Analyzing

Although web scraping is a blessing for experts and programmers, people who are not so good in programming can face difficulties in analyzing and performing it. However, it is not a significant issue and can be resolved with a little brainstorming.


2. Data Analysis

When data is scraped from the website, it needs to be read and understood correctly to process, which can be a time taking and energy-consuming process.


3. Data Analysis

Crawling of large websites requires enormous amounts of requests sent by the same IP address, and sometimes, websites have the policy of banning the IP addresses. It is one of the major problems but is solved by proxy scrapers.




The Tech Platform

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