Difference Between Parsing and Crawling

Sometimes people speak of these two concepts as interchangeable. But in reality, there is a difference between them. If you want to know the difference between parsing and crawling, you've come to the right place.

Short Answer

The short answer is that parsing is extracting data from one or more websites, while crawling is searching for or discovering URLs or links on the web.

Typically, in web data extraction projects, you need to combine crawling and parsing. So first you crawl (or discover) URLs, download HTML files, and then extract data from those files. This means you extract data and do something with it, such as storing it in a database or processing it further.

What's the difference?

Looking deeper, there is a big difference in the purpose of these two things and how they work.

Parsing deals with data, specifically data fields that you want to extract from certain websites. When parsing, you usually know the target sites. You may not know the URLs of specific pages, but you at least know the domains.

When crawling, you most likely do not know specific URLs and probably do not know the domains. That is precisely why crawling is needed: you want to find URLs so you can do something with them later. For example, search engines crawl web pages to index them and display them in search results.

Another example of data discovery is when you have one site from which you want to extract data—in this case you know the domain—but you don't have the URLs of the pages on that specific site. You don't know which pages to scan. So first you create a crawler that will output all the page URLs that interest you—these could be pages in a specific category on the site or in certain parts of the site. Or, for example, the URL must contain some keyword, and you collect all those URLs—then you create a parser that extracts predefined data fields from those pages.

What is the end result?

When crawling, the end result is much simpler—it's just a list of URLs. There may be other fields, but the main elements are the URLs.

And when parsing, there are usually many more fields—5, 10, 20 or more data fields. The URL may be one, but when parsing, you extract data not necessarily for the URL but for other data fields that appear on the site. Depending on the specific use case, it could be the product name or price, or some text, or other information from any type of website.

Getting data directly

For businesses, it makes sense not to worry about crawling and parsing, so they can focus solely on getting insights from that data. Data parsing partners like ESK Solutions can handle all the hassle of data collection. Just tell us what data you need.

Learn more about parsing

ESK Solutions has been working in the field of parsing for 5 years. During this time, we have accumulated vast experience and knowledge in data extraction.