What is web scraping? Complete guide to the basics.

Intro to the basics of web scraping: what it is, how it works, real-world use cases, and how to start.

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What is web scraping?

Web scraping is the process of automatically extracting data from a website. You use a program called a web scraper to access a web page, interpret the data, and extract what you need. The data is saved in a structured format such as an Excel file, JSON, or XML so that you can use it in spreadsheets or apps.

What is web scraping: diagram showing data going from website through scraping platform to structured data

You could do this manually by copying and pasting, but scraping is typically performed using an automated tool that can pull data at scale from web pages and do it very fast.

What is the definition of web scraping?

Web scraping is the automated process of extracting data from a website. Web scraping is also known as web harvesting, data extraction, web data extraction, data scraping, and data mining.

You might also hear it called screen scraping, but that's something a bit different.

What is web scraping? What is web scraping? Globe with the words web scraping surrounded by forms of data

What's the point of web scraping?

It's already impossible for humans to process even a fraction of the data on the web. That's why web scraping has become an essential tool. We need machines to rapidly read that data for us so that we can use it in new and interesting ways.

To give you some idea of what I mean, imagine how long it might take you to manually copy and paste text from 100 web pages. A machine could do it in less than a second if you give it the correct instructions. It can also do it repeatedly, tirelessly, and at any scale.

Forget about 100 pages. A computer could deal with 1 million pages in the time it would take you to open just the first few!

Web scraping can be used for everything from academic research to business intelligence. It's used to gather data at scale on product prices, weather information, market trends, and much more.

How do web scrapers work?

Web scrapers operate by sending HTTP requests to a web server, the same way that a browser does when you visit a site. Once the server responds with the page's HTML code, the scraper parses (basically, it breaks it down and tries to understand it) this code to locate particular HTML tags, classes, or attributes that contain the data to be scraped.

Most information on a web page is "wrapped" in tags that enable the browser to make sense of it, and it's these tags that make it possible for scrapers to get what you need.

Web scrapers can extract data from multiple web pages at a time, making them great for large-scale data mining.

What is web scraping? Structured data from web scraping.

What is scraping data?

Scraping data is the point of web scraping. It's all about getting that juicy unstructured data and transforming it into something more useful.

This unstructured data might include text, images, prices, contact details, or any other information publicly displayed on a web page.

The scraped data is often cleaned, turned into structured data, and stored in a database or file for further analysis or use. Structured data is just a way to say that the information is easy for computers to read.

Web scraping is used to extract what type of data?

Web scraping can be used to extract lots of different types of data from the internet. It can gather textual information such as product descriptions, prices, contact details, and customer reviews, as well as visual content like images and videos.

Depending on the use case, you can target specific data such as real estate listings, stock market trends, job postings, market research, or travel fares. It's also used for lead generation, to collect sentiment data from social media, news articles for content aggregation, content scraping by the media, and scientific data for academic research.

What is web scraping? Image of futuristic computer with data.

What is web scraping used for?

Lead generation

Web scraping is used to gather contact information and details about potential business leads from various online platforms. By collecting data from websites like LinkedIn, businesses can identify and target specific demographics. This kind of contact scraping can generate better leads.

Market research

Understanding market dynamics is crucial for any business. Web scraping allows analysts and researchers to collect vast amounts of data from various sources. This information, which might include customer reviews, competitor strategies, or market trends, helps to build a comprehensive picture of the industry landscape and enables brand monitoring.

Price monitoring and competitive intelligence

Price monitoring involves tracking the fluctuations in the prices of goods or services over time. It lets businesses keep an eye on these changes, allowing them to adapt their pricing models and strategies.

Competitive intelligence takes the concept of price monitoring a step further by employing advanced analytics and insights gathered through price scraping. Combining competitor analysis with market trends, customer behavior, and other influencing factors, can lead to a more nuanced and strategic approach to pricing.

Real estate listing scraping

In the real estate industry, web scraping is employed to gather detailed information about properties listed online. This can include everything from location and price to features and photos. By consolidating this data, real estate professionals can offer more tailored online services to their clients and stay ahead of market trends.

Sentiment analysis

Web scraping plays a vital role in sentiment analysis by gathering opinions, reviews, and comments from social media, forums, and review sites. Market research companies can analyze this data to gauge public sentiment about products, services, or brand image, enabling them to respond to customer needs and preferences effectively.

Job market analysis

Recruitment agencies and HR professionals can make use of web scraping to monitor job postings on sites like Indeed. By analyzing job descriptions, salary trends, and skill requirements, they can gain insights into labor market dynamics, helping both employers and job seekers.

Academic research

Researchers and academics can use web scraping to collect data from publicly available sources for scientific studies and analyses. This can include information on climate patterns, historical documents, social behavior, or data for generative AI or machine learning.

Travel fare aggregators

Travel aggregators and comparison sites use web scraping to gather information on flight fares, hotel prices, and vacation packages from various providers. This enables them to offer customers an overview of available options and pricing.

News and content aggregation

Web scraping enables media companies and news aggregators to collect articles, blogs, and news stories from different sources. This content scraping assists in creating centralized platforms where users can access diverse content from various publishers.

Stock market analysis

Investors and financial analysts use web scraping to track stock prices, market news, and financial reports. By continuously monitoring relevant data, they can identify trends, make predictions, and formulate investment strategies aligned with market movements.

Healthcare data extraction

In the healthcare sector, web scraping can be used to collect data on disease outbreaks, medical research, patient reviews, and more. This information can support public health initiatives, medical studies, and healthcare service improvements. Scraping was used extensively during the COVID-19 pandemic.

Comparison websites

Comparison websites are a great example of how web scraping can benefit consumers. These platforms use web scraping to extract data on products or services from online retailers and service providers. Aggregating information such as prices, features, customer reviews, and availability, lets these websites present users with a side-by-side view of their options.

What are the benefits of web scraping?

Web scraping gives anyone the means to access and analyze vast amounts of data from the web. That's a powerful tool. But there are some pros and cons, so you should be aware of those.

But at the end of the day, automating the data collection process means that web scrapers save time and resources. And that's a massive benefit for any business.

What is web scraping? Illustration of data points on the web.

Want to start web scraping?

Visit Apify Store if you just want to use a pre-built scraper. You can find scrapers there for e-commerce websites, lead generation, and more. If you can't find what you need, you can request a web scraper from our certified Apify partners.

And if you're ready to build your own web scrapers, check out our Web Scraping Academy. It has a great web scraping for beginners section, along with more advanced web scraping courses.

The Apify blog also has plenty of tutorials and guides on how to use various different methods to extract data from websites.

FAQ

How do I extract data from a web page?

Here's a step-by-step explanation of the process of extracting data with a scraper:

  1. Identify the URL(s): Determine the web page(s) containing the data you want to extract.
  2. Send a request: Use tools or code to send an HTTP request to the identified URL.
  3. Parse the HTML: Use parsing methods to navigate through the HTML code of the page.
  4. Extract the data: Locate and retrieve the specific information needed from the HTML.
  5. Clean and structure: Process the extracted data into a usable structured format, such as an Excel spreadsheet or database.

What is the difference between a web crawler and a web scraper?

Web crawlers and web scrapers serve different functions. A web crawler, also known as a spider, systematically browses the internet to index web pages. Its core purpose is to discover and navigate websites. Web crawling is often used by search engines to update their indexes.

But a web scraper is designed to extract specific information from web pages. While a crawler moves through sites to find pages, a web scraper focuses on pulling data from those pages.

What is web scraping with Python?

Web scraping with Python uses the Python programming language to gather data from websites. Python is a popular choice for web scraping because of its simplicity and a rich ecosystem of libraries like Beautiful Soup, Scrapy, and Selenium. These libraries provide functions to send HTTP requests and navigate HTML code.

Is web scraping easy?

That depends on the complexity of the website being scraped. For simple data extraction from a website with a clear and consistent structure, scraping can be relatively straightforward, especially with the aid of various tools and libraries designed to facilitate the process.

Scraping more complex sites that use dynamic content loading, anti-scraping measures, or intricate HTML structures can be challenging even for experienced developers.

Can AI do web scraping?

It's possible to combine AI algorithms with web scraping processes to automate some data extraction activities, such as transforming pages to JSON arrays. AI web scraping is more resilient to page changes than regular scraping as it doesn’t use CSS selectors. However, AI models are currently restricted by limited context memory and other factors. We're constantly exploring AI and web scraping trends, but we don't predict that the entire scraping industry will switch to AI anytime soon.

What is an example of scraping?

Imagine an online electronics retailer scraping information from rival websites. The retailer extracts data on pricing, features, and customer reviews. The price scraping might reveal that competitors are pricing certain items lower or offering unique bundles.

By analyzing customer reviews and ratings, the retailer can gain insights into what customers value most and what areas might need improvement.

The retailer can then adjust their pricing strategy, introduce similar bundles, or explore new market opportunities. This ongoing strategy helps them stay competitive, respond to market changes, and better understand customer preferences.

What is web scraping? Illustration of wall of data.

Yes, web scraping is legal, but the legality of extracting data from a website can depend on the website's terms of service, the nature of the scraped content, and how the scraping is conducted.

The most common myth is web scraping is illegal. That's simply not true. Web scraping is legal, but there are some rules.
-- Ondra Urban, Apify COO

If you're worried, please read our extensive blog post on the legality of web scraping, or watch our informal talk on whether web scraping is legal on YouTube.

What is ethical web scraping?

We believe that there are 5 main principles to ethical web scraping, with some of those principles applying to websites that contain data:

  1. Don’t overburden the target website
  2. Respect the creators of the data you scrape
  3. Honor the open web
  4. Don’t seek to monopolize data
  5. Don’t block scrapers without good reason

Read more in our post on ethical web scraping.

Can websites tell if you scrape them?

Yes, website owners can detect web scrapers. Activity like rapid, repeated requests from the same IP address or behavior that doesn't align with typical human browsing can trigger alarms. Many websites use anti-scraping measures such as CAPTCHAs or block IP addresses to block scrapers.

Can you get banned for web scraping?

Yes, you can get banned if you violate a website's terms of use or engage in activities that the site considers abusive. Bans may involve IP blocking, account suspension, or other measures to prevent further access.

What is web scraping? Illustration of robots extracting data.

What are some good web scraping tools?

If you're a developer, libraries like Beautiful Soup and Scrapy in Python offer flexibility and power. Apify is another strong option, with both ready-made web scraping tools and a mature platform for custom scraper development. Apify also supports and maintains Crawlee, a modern open-source web scraping library. For the less technical, tools like Octoparse and ParseHub provide intuitive graphical interfaces to scrape data without writing code. Selenium, Playwright, and Puppeteer are popular tools that are especially useful for handling dynamic content loaded via JavaScript. The future of web scraping is also being affected by the rise of AI web scraping tools.

Are browser extension web scrapers as good as dedicated scraping tools?

Browser extensions allow users to scrape data directly from the browser. They're user-friendly and are good for simple, small-scale tasks.

Dedicated scraping tools and web scraping software are designed with more complex tasks in mind. They're more flexible, can handle large volumes of data, and often come with features like proxy management and CAPTCHA solving.

Should you build your own web scraper or use a pre-built scraper?

Writing your own web scraping code gives you complete control over its functionality. If you have unique requirements or need to scrape websites with unique HTML site structures, building your own might be the way to go. But it will need significant technical expertise and can take a long time.

Using a ready-made scraper gives you a quicker and more user-friendly way to get started. A pre-built scraping tool will also often include built-in features to handle common scraping challenges.

Ondra Urban, Apify COO, recently shared 6 things you should know before buying or building a web scraper.

Should you run your scraper on the cloud or locally?

Running a scraper locally means that it operates on your personal computer or server. This gives you direct control and might be simpler to set up, but it may limit scalability.

Cloud-based scraping means easy scaling, better reliability and speed, and often includes advanced features like proxies, IP rotation, monitoring, API access, and distributed scraping bots. Local scraping suits smaller projects, but cloud scraping is better for large-scale scraping or long-running tasks.

Basic scraping terminology

Web scraping: The process of automatically extracting data from websites. Also known as screen scraping, web data extraction, web harvesting.

Web scrapping: This is just a really common and easy-to-make typo!

Web crawling: Web crawlers are spiders or spider bots that systematically browse the web and index it. Search engines use these bots to make it easier for us to search the web.

Structured data: Information that is organized and formatted in such a way that it is easy for computers to read and store in databases. A spreadsheet is a good example of how data can be organized in a structured way.

Hypertext Transfer Protocol (HTTP): Enables computers to retrieve linked resources across the web.

Hypertext Markup Language (HTML): The markup language of the web. Allows text to be formatted so that it can be displayed correctly.

Uniform Resource Locator (URL): A “web address”. Used to identify all the resources on the web.

Cascading Style Sheets (CSS): The design language of the web. It enables web page authors to style content and control presentation across an entire website.

JavaScript: A programming language used all over the Internet to control the behavior of websites and enable complicated interaction between user and web page.

IP address: An Internet Protocol address is a number assigned to every device on the Internet. These numbers allow devices to communicate with each other.

Proxy: A proxy server is a device that acts as an intermediary between other devices on the Internet. Proxies are commonly used to hide the geographical location of a particular device, often for privacy reasons.

Application Programming Interface (API): A computing interface that makes it possible for multiple different applications to communicate with each other. An API operates as a set of rules to tell the software what requests or instructions can be exchanged and how data are to be transmitted. Apify got its name from API 😉

Software Development Kit (SDK): A package that enables developers to create applications on a particular platform. An SDK can include programming libraries, APIs, debugging tools and utilities designed to make it easy for a developer to use the platform. Apify has its own SDK.

Apify makes web scraping easy

David Barton
David Barton
Apifier since 2016 so learned about web scraping and automation from the experts. MSc in Computer Science from TCD. Former game designer and newspaper production manager. Now Head of Content at Apify.

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