Web crawling vs web scraping

These two terms are sometimes used interchangeably in conversations. However, there’s actually a meaningful distinction between them. Wondering about the difference between web scraping and web crawling? You’ve come to the right place.

The short answer

In simple terms, web scraping focuses on extracting data from one or multiple websites. Crawling, on the other hand, is concerned with finding or discovering URLs and links across the web.

Typically, web data extraction projects require combining both crawling and scraping techniques. The process involves first crawling to discover URLs, downloading the corresponding HTML files, and then scraping the desired data from those files. This extracted data is then processed further, such as being stored in a database or undergoing additional analysis.

What’s different?

Looking more closely, there’s a substantial difference in both the purpose and methodology of these two approaches.

Web scraping centers entirely around data – specifically the data fields you want to extract from particular websites. When scraping, you typically have knowledge of your target websites. While you might not know the exact page URLs, you at least know the domains you’re working with.

With crawling, you likely don’t know the specific URLs, and you probably don’t know the domains either. This uncertainty is precisely why you crawl: to discover those URLs for later use. Search engines provide a perfect example – they crawl the web to index pages and display them in search results.

Another crawling scenario occurs when you have a specific website from which you want to extract data – meaning you know the domain – but lack the individual page URLs of that website. You’re uncertain which pages to scrape. In this case, you first build a crawler that outputs all relevant page URLs – perhaps pages within a specific site category or particular website sections. Maybe the URLs need to contain certain keywords, and you collect all matching URLs – then you develop a scraper to extract predetermined data fields from those pages.

What is the end result?

Web crawling produces relatively straightforward output since it’s primarily a list of URLs — additional fields may be included, but URLs remain the main elements.

Web scraping typically involves many more fields – anywhere from 5 to 20 or more data fields. While the URL might be included, when you scrape, you’re extracting data not necessarily for the URL itself but for other data fields displayed on the website. Based on the business requirements, these might include product names, product prices, text content, or other information from various website types.

Get web data directly

For businesses, it makes sense to not worry about crawling and scraping so you can focus purely on the insights from that data. Web data partners like Webparsers can take care of all the hassles of web scraping. Just tell us what data you need.

Help me access web data

Learn more about web scraping

Here at Webparsers, we have been in the web scraping industry for 12 years. We have helped extract web data for more than 1,000 clients ranging from Government Agencies and Fortune 100 companies to early-stage startups and individuals. During this time we gained a tremendous amount of experience and expertise in web data extraction.

Here are some of our best resources if you want to deepen your web scraping knowledge:

• Web scraping: Best practices
• Enterprise web scraping: A guide to scraping at scale
• Legal compliance in web scraping
• The build in-house or outsource decision
• Price intelligence: Everything you need to know about price crawling
• Price intelligence Data knowledge hub

FAQs

What is web scraping?

Web scraping is the process of extracting specific data fields from websites, such as product names or prices.

What is web crawling?

Web crawling involves discovering or finding URLs on the web, often used to create a list of pages to scrape later.

How are web crawling and web scraping different?

Web crawling focuses on discovering URLs, while web scraping focuses on extracting data from known or discovered pages.

Can web crawling and scraping be combined?

Yes, web crawling is often used to first find URLs, and then web scraping is applied to extract data from those pages.

What kind of data is extracted in web scraping?

Web scraping typically extracts multiple data fields such as product names, prices, or text from websites.