What Is Web Scraping? A Beginner's Guide

Websites carry a wealth of invaluable data. Product prices, job postings, stock quotes, business listings, search engine rankings, and more - there is so much data that exists out there on the public web. 

However, this data is often unstructured and scattered around on pages across websites. How can we collect, structure, and re-organize this data to repurpose it, e.g. for better decision making and building new experiences? Well, web scraping is the answer.

What Is Web Scraping?

Web scraping, also called data scraping or web data extraction, is an automated process for collecting data from websites. The automated programs, called bots or crawlers, visit and interact with a large number of pages, parse out valuable information and save it into structured data formats suitable for programs like spreadsheets, databases, and analytics tools.

Web scraping has use cases across many different industries. Businesses use it for collecting data for lead generation, price monitoring, market research, building aggregated experiences, social media, and news monitoring, and much more.

Web Scraping vs. Web Crawling

While you’re on the subject of web scraping, the two mixed concepts that will often pop up are web scraping and web crawling. While sometimes people use the terms interchangeably, there is a difference.

You already have the answer to what is data scraping. How is crawling different from scraping?

Web crawling involves a systematic and exhaustive exploration of the websites by discovering URLs, typically for the purpose of downloading and indexing content for later use. Search engines use web crawling to find URLs and index them for displaying in the search results.

Web crawlers generally operate at scale and use intelligent automation to source data from thousands, millions, or even billions of web pages across many different websites.

Starting with an initial set of URLs, known as the seed URLs, a web crawler, or crawl bot, identifies all the hyperlinks on the pages it crawls and adds them to the list of URLs it will visit next. Web crawlers work in a loop.

Guess, how Google and Bing discover and index information anywhere from the internet? That’s right. They do web crawling. They crawl the web 24x7 at a gigantic scale.

To sum it up, web scraping is more about targeted data extraction from one or more websites, while web crawling focuses on iteratively discovering links on the web. Web data extraction projects typically involve both.

How Web Scraping Works

At a very high level, this is how the web scraping process works:

1. URL Discovery: Identify the targeted websites and develop a strategy to discover URLs of the pages you want to extract data from. It could be all, or a subset of, pages on the website. URL discovery would typically involve techniques like crawling, URL synthesis, sitemap exploration etc.
2. Downloading: Make HTTP requests to the target URLs to download the HTML content from the page. 
3. Extraction: Use parsers to extract pieces of information from the pages that are meaningful to you. It could be text fields, numbers, tables, links, images etc.
4. Transformation: Clean, sanitize and transform the extracted data into the desired format, and export it to a suitable file format, such as CSV, JSON, or XML.
5. Quality Assurance: Apply quality checks to ensure everything in the process worked as expected, and the data meets the completeness and accuracy standards.

What Is Web Scraping Used For?

In today’s competitive landscape, data means power. With the internet at your disposal, you’re sitting on a goldmine! Data scraping is just the tool to tap into the quarries - websites, to be precise - and rise above the competition. 

Listed below are some of the most common uses for web scraping across different industries. Of course, this is not an exhaustive list, the possibilities are endless!

Price Intelligence

Monitoring competitors’ prices and using them to help inform your own is important for e-commerce and retail businesses. Doing it manually is practically impossible even for a few hundred SKUs.

Web scraping can be used to retrieve pricing data from competitors’ websites at regular intervals (hourly, daily, weekly, etc.) in a format that can be exported to spreadsheets or other analytics tools. 

Product Enrichment

This is another common use case of web scraping in the e-commerce industry. Web scraping can be used to acquire images and product attributes - descriptions, features, specs, etc. - from online sources. These attributes typically come from manufacturers, and it is much easier and cheaper to reuse them than create them on your own.

Lead Generation

Lead generation is a popular use case of web scraping across almost every industry. Scraping yellow pages and online directories to collect contact information of potential customers can help you target marketing campaigns effectively. Head to this link to learn more about how data scraping can help you generate quality leads.

Market Research

Understanding the market is critical to every business. Web scraping is the fastest way for harnessing large volumes of high-quality data to derive invaluable market insights. Scraping social media forums for the latest buzz in your niche can give you an edge on market trends. Scraping web data also helps you optimize influencer marketing, distribution channels, and product placement to maximize returns. 

Content Aggregation

A 2010 research by American Life Project revealed that 61% of Americans obtain at least some of their news from online sources. And that’s the pain point news aggregator websites can monetize. News aggregators gather data by scraping news websites to sort and display a list of short snippets of featured news articles on their dashboards. Clicking on the article takes the user to the original source.

Other than news aggregation, web scraping is the core technology behind price comparison sites and travel aggregators. Unleashing web scraping to build aggregator sites offers some exciting opportunities to entrepreneurs.

Other Uses

Data scraping is a powerful tool for almost every industry. Scraping published research papers, economic data or statistics can feed research. Scraping online job postings can provide data for lead generation and market research.

Here is a more comprehensive list of web scraping use cases across different industries.

How To Start With Web Scraping?

Now you know what web scraping is and how you could possibly use it to solve your data problems, you might be wondering what would be the easiest and fastest way to get started. There are broadly two paths you can choose.

The Do It Yourself Option

If your task is small and straightforward, and you have the time to learn a tool, using a self-service scraping tool might be a good start. These tools work by allowing you to train them for a few sample pages, by defining interactions and tagging elements on the page you would like to extract.

There is a sharp learning curve though and HTML knowledge may be required to activate the advanced features.

Challenges To Overcome

Though it may sound simple to code yourself a web scraper, there are a few challenges to keep in mind. Other than the advanced programming skills you’ll need to create a custom-made web scraper, you should also have a robust infrastructure to monitor and employ timely changes in the scraper. As the HTML source of the websites you want to scrape changes, you’ll also need to make suitable changes to your parser for the process to continue uninterrupted. 

Furthermore, many websites keep their data in Javascript instead of HTML, posing further complications to your scraper design. Executing captchas and combating anti-bots are also some of the common challenges web scrapers face. 

Partnering With A Web Scraping Service

Is there a way to skip the challenges and enjoy all the perks of web scraping just the same? 

Professional web scraping services take care of all technical aspects for you. It allows you to spend more time utilizing the scraped data rather than spending time overcoming the complexities and challenges of maintaining web crawlers. 

Talk to a data expert to discuss possibilities for your business and learn how CrawlNow caters to your specific data collection needs with its powerful web scraping solutions.

Legality Of Web Scraping

The presence of misleading information on the internet, often, raises questions about the legality of web scraping.

First of all, web scraping itself is completely legal. If it was illegal, Google and many other great applications we depend on in our daily lives would not exist. Web scraping is simply a tool to copy information from websites. Like any other tool, it can be used for the good or the bad.

However, when scraping websites, you’ll often encounter copyrighted data, personal data, or other kinds of data that may be protected by the law. To scrape or not to scrape is a common dilemma in such cases. And if you do decide to scrape, the next big question is how to scrape it to avoid any legal complications. We have a comprehensive guide clarifying the legality of web scraping to help you benefit from data extraction without violating any laws.