Web Crawling VS Web Scraping

Web scraping and web crawling are often used interchangeably. They’re both used for data mining, right?

Yes, but they are not the same thing. In this article we’ll look through the key differences between web scraping and web crawling as well as help you decide which one is relevant to you.

Web Crawling vs scraping

Key Differences

In layman’s terms, web crawling is what search engines do: going through the web, looking for any information, clicking on every link available.

It’s quite a generic process with the goal of collecting as much information as possible (if not all) on the needed site. Basically, it's what Google is up to - view the page as a whole and then index all information available.

Web Crawling with Smartproxy proxy network
Web scraping with Smartproxy proxy network

If you want to download the information gathered, you’d want to go for web scraping instead. Web scraping (sometimes referred to as web data extraction) is more of a targeted process.

You can tweak the commands and scrape very specific information from your target website using scraping proxies. You can then download the results in a relevant format (e.g. JSON, Excel).

There might be some cases where you’d want to use both web crawling and scraping to accomplish one goal, almost using them as step one and step two in your process. With both combined, you can get large sets of information from major websites using a crawler and then extract and download the specific data you need using a scraper later on.

What Software Should you Use?

Another big difference between the two is the software used. For web crawling tasks, you’d want to use a crawler, most of the time lovingly referred to as spider (or an automatic indexer if you have something against spiders).

web crawler task

As for scraping, there are plenty of different tools out there, referred to as scrapers. Which one you want to use depends on what your preferred scraping methods are.

web scraper task

If you're a beginner, we'd recommend going with ParseHub or Octoparse, if you prefer Python - try Scrapy or Beautiful Soup. And if you're more of a NodeJS kinda guy, look into Cheerio and Puppeteer.

Crawling vs Scraping: Examples

For you to pick whether you need to scrape or crawl, it would be useful to see what can be done with both of the methods. First, let’s take a look at an example how you can use web scrawling to your advantage.

If you want to audit your own website, check for broken links and generally do some SEO guru magic, you might want to look into Screaming Frog, a SEO crawler. With the software crawling your website, it can detect 404 errors, analyse your Meta Data, find duplicates - all in all, collect all information possible.

screaming frog with Smartproxy proxies

As for web scraping, a popular use case example would be price intelligence research. Basically, if you wanted to sell a particular item on Amazon, you’d need to get some idea what the price range for similar products is. This is where you put a scraper to work (if you’re a beginner - you can’t go wrong with Octoparse). We won’t go into the nitty gritty of it in this article, but after your project is done, you’d end up having a list of items, URLs and their prices. Of course, you can expand or narrow the information you want to extract according to your needs. Pretty neat, isn’t it?

Frequently Asked Questions about Crawling and Scraping

Is web scraping legal?

When you are web scraping publicly accessible factual data, it is legal. Always read and follow your target's Terms of Use and robots.txt file. Always consult your lawyer before scraping a target.

Is scraping Amazon legal?

Even though Amazon doesn't preach it, it is legal. Prices, reviews and what-not are all available to everyone anyway.

What is the difference between spider and crawler?

Spider and crawler can be used interchangeably when referring to a software used for web crawling. It can also sometimes be called an automatic indexer.

Is scraping and crawling the same thing?

While they sound very similar,they are not the same. Web crawling is a way to get the information and organise it, while web scraping can get very specific data and store it for later use.