Web scraping is the process of extracting data from a website. It does this by lifting the actual HTML code, parses it into a form that a computer can use, and then the content is exported to a file, often a spreadsheet. Scraping can be done through simple cutting and pasting, but this is time-consuming and may alert the site to the user’s IP address, resulting in a ban from the site. There are techniques and tools for web scraping, some are easy to use, and others can be quite technical.
Scraping can be done through several HTML parsing methods, which employ Javascript to single out linear or nested HTML pages. DOM Parsing provides a detailed view of the page’s layout and the location of nodes that contain information for scraping. XPath can be used to select nodes in an XML document. Google Sheets will scrape texts with the IMPORT XML feature.
In addition to more technical methods for scraping, there are user-friendly tools for beginners. Many of these are available for free and require no knowledge of coding. Sites with login, such as Facebook, pagination, or dynamic content, may be more challenging to scrape and may require a high-quality web scraping tool.
Installing a browser extension scraper will allow you to lift content from websites quickly. Some can scrape data immediately from URLs that you provide. Browser scraping tools, such as those that work with Google Chrome, are ideal if you do not require large amounts of data and need fast scraping.
What Is a Web Crawler?
Sometimes the terms “web scraping” and “web crawling” are used interchangeably, but the processes and the purposes are quite different. Web crawling mimics what search engines do through tools called “spiders.” These web crawlers or spiders search the internet for content that fits what you are looking for, kind of like Google search results.
Crawling is the method of locating large amounts of data across the web relevant to your purpose. If you want to download, use, and analyze the data, web scraping is the correct operation to use. Often, web crawling is the first step to web scraping, and its job is to locate any information or content that may be useful before deciding to select and scrape portions of it.
Web crawling techniques include selective crawling, which is locating and organizing URLs by categories, incremental crawling, a gradual process that continually updates URLs, and replaces old ones with new. Tech experts may design their crawlers or spiders, or for those who are new to crawling, there are tools available that will automate the process.
Tips for Using a Web Scraper
The instructions for using a web scraper depend on which kind you have installed. Some methods require technical knowledge, whereas others are ideal for first-time scraping. Scraping tools often have video tutorials with detailed instructions.
There are special considerations based on how much content you intend to scrape, whether you use a browser extension to extract data and store it on the Cloud. You will also need to take into account pagination, dynamic content, or log-ins. When scraping, it is good to use a VPN to disguise your actual IP address, so websites don’t block you from taking too many actions.
Tips for Using a Web Crawler
The first step for web crawling is to determine how specific or general you want the search to be. Do you want the spider to return a wealth of choices, or do you prefer a more focused search? Crawling for data with IP rotation with the help of a proxy will keep your crawling private and prevent websites from detecting crawling activity.
Advantages of Web Scraping
The main benefit of web scraping is that it allows you to retrieve data from sites for research or marketing purposes. Businesses can research competitors, including their pricing information, content, and keywords. Scraping is more efficient than cutting and pasting and can yield large amounts of data in a relatively short amount of time.
Advantages of Web Crawling
Web crawling allows you to locate all of the relevant data on a certain topic. Crawling can be general or specific, depending on how much data you require in a particular category. If you are not yet sure what information you need to scrape, preliminary web crawling is recommended to refine your search and help you form an idea of the kind of content you want to scrape.
Access More Data
Although they involved different processes, web scraping and web crawling are alike. They let you have access to any information you need on the web, whether you want to audit a site, take a look at content on a specific topic or if you need to extract large amounts of data from the web. Research, marketing, and analysis are easier with web crawling and web scraping, and there are tools available to make perusing and retrieving content easier.