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Data crawling vs web scraping: Key differences and use cases

Data crawling and web scraping often get confused in the data industry. Both processes are similar but they differ in purpose and practical application

Introduction

Data crawling and web scraping often get confused in the data industry. Both processes are similar but they differ in purpose and practical application. Despite their overlap, it’s important to understand these differences. Data crawling is the cyclical process of discovery. Web scraping is the targeted extraction of structured data from specific sites.

People often confuse these two due to their similarity in process: Fetch a site and store content. However, their differences are much more nuanced. By the end of this article, you’ll be able to answer the following questions.

  • What is data crawling?
  • What is web scraping?
  • Why do people confuse the two?
  • How are crawling and scraping used together?

What is data crawling?

Data crawling is a cyclical process. A crawler fetches a site, finds all its links and adds them to a list called a “queue.” The crawler stores raw page data. Then it targets another link from the queue. This process continues indefinitely. The crawl only ends when the queue has been emptied or someone manually shuts off the crawler.

When crawling, we usually index the entirety of a website. Projects like Common Crawl attempt to index as much of the web as possible. Then they store raw page data in a compressed format. Targeted crawls are common but they too index the site as a whole — if you crawl a site using Scrapy, it attempts to index the entire site by default.

A typical crawler runs the following cyclical workflow. The process repeats until we run out of links or turn off the crawler.

  1. Fetch a URL
  2. Save raw page data
  3. Add links to a queue
  4. Get another link from the queue and repeat

Data crawling is used to power search engines. Teams utilize crawlers to monitor websites for changes. Crawling fuels large-scale data collection processes for raw, unstructured data.

What is web scraping?

Web scraping is the process of extracting structured or semi-structured data from a specific target: Product information, blog posts, news articles and social discourse. Imagine you’re scraping GitHub to train an AI coding assistant. You’d extract structured information from the repos: Stars, README files and code snippets.

When we scrape the web, we use a variety of methods to extract specific data from raw HTML. Rather than saving page links, we might pull e-commerce listings with price information, product descriptions, reviews and availability. These methods often power Application Programming Interfaces (APIs) used by most modern software today. For instance, Bright Data offers e-commerce scrapers that parse the page and return this information directly.

A typical web scraper follows the steps you see below. Once the data’s been saved, the scraper shuts off.

  1. Fetch a URL
  2. Extract structured data
  3. Format the extracted data (usually into JSON)
  4. Save to a database, CSV or JSON file

Web scraping is used to extract targeted data from a page. It’s used everywhere for things like sentiment analysis, e-commerce intelligence and AI training. In production systems, scraping can often take place during a crawl. This is where much of the confusion stems from.

How data crawling and scraping work together

In practice, data crawling and web scraping are often used in tandem — especially with AI integration. Before AI-powered extraction methods, web scrapers needed to be hardcoded. Now, scrapers are often built using AI for dynamic extraction on the fly. With AI at the helm, an AI agent can orchestrate a crawler and run extraction operations as soon as content has been discovered.

Take a look at the joined workflow below. The main data crawling loop remains intact. However, during the crawl, a web scraping workflow branches off from the loop. Using this conjoined workflow, we can also remove the raw data storage from the crawling loop — the scraping branch already extracts and stores the important data.

Combined data crawling and web scraping workflow
Combined data crawling and web scraping workflow

Here are a few examples of potential implementations in different industries.

  • E-commerce: An AI agent manages a data crawler while viewing the page in real-time using a remote browser like the Bright Data Browser API. The agent crawls a variety of retailers with different layouts. When it identifies products, it dynamically extracts and stores them for human review — regardless of page layout.
  • News: A data crawler monitors news sources and utilizes an SERP API like those offered from Bright Data and SerpApi. It also uses social media scrapers like the ones offered from Bright Data and Zyte to monitor for stories that haven’t broken into the mainstream news yet.
  • Social media: The same social media scrapers mentioned above can be integrated with crawlers custom built to crawl aggregate social media sites. Posts and conversations of interest can be extracted and stored for later review and usage. Once a crawl finishes, it can restart the cycle immediately for continual monitoring. This is especially useful in terms of real-time sentiment analysis.
  • Healthcare: Data crawls can be used in a simultaneous workflow to monitor sales of over the counter (OTC) medicines alongside social media posts. This allows for tracking of real-time correlation between reported symptoms and market reactions to trends in illness.
  • Defense: When managed by an AI agent, a data crawler can monitor all of the above sites in tandem, while an AI agent extracts relevant intelligence information to monitor global threats.

In today’s world, we need real-time data crawling and web extraction simultaneously. When combined with AI, these technologies allow us to conduct real-time intelligence gathering, monitoring and analysis in nearly every industry.

Tools and choosing the right approach

There are a variety of frameworks and tools available for data crawling and web scraping. Your choice of tooling depends on your individual project needs. Ask yourself and your team the following questions.

  • What sort of data are we looking for?
  • Is the data already structured?
  • How often do our crawlers need to run?
  • What data do we need to extract?
  • What does our budget permit?
  • What are we looking for in a Service Level Agreement (SLA)?

Crawling tools

  • Bright Data Crawler API: Define a URL and retrieve the entire website in a variety of formats: Markdown, JSON, HTML or text.
  • Firecrawl: Input a URL and get the site as Markdown, screenshots, HTML, links or JSON.
  • Scrapy: One of the most popular open source scraping frameworks. It doesn’t come with SLAs or no-code options but Scrapy remains one of the most popular crawling options due to concurrency and extraction features all available from within your Python environment.

Scraping tools

  • Bright Data: Bright Data offers a variety of prebuilt scrapers and custom scrapers alongside APIs for remote browsers, SERP, web unblocking, natural language extraction and headless browsing.
  • Firecrawl: Firecrawl’s extract feature allows teams to define their scraping operation via natural language. Tell their AI what you want and it extracts the data from the target site.
  • Apify: Using their Actor framework, you can access a variety of scraping tools as needed. Prices and tool quality can vary across their Actor Store. Actors are provided by both Apify themselves and community developers.
  • Headless browsers: Playwright and Selenium let you control browsers using open source frameworks without enterprise-grade support. Extraction is available but you need to manage these solutions by setting up AI agents or hardcoding your own extractors.
  • Static Parsers: Tools like BeautifulSoup and Cheerio allow you to parse static HTML pages. They can’t load dynamic pages but work well in minimalist setups.

Ultimately, your choice of tooling depends on your project needs. If you only need to parse static information, static parsers might be a viable option. Headless browsers can be effective for teams requiring occasional community support. For enterprise-grade projects, the commercial options mentioned above can drastically reduce headache and improve productivity, offering stable data crawlers and reliable data extraction for web scraping.

Key differences between crawling and scraping

AspectData crawlingWeb scraping
PurposeDiscovery — find and queue new pages across the webExtraction — pull structured or semi-structured data from known pages
ScopeBroad collection (entire sites, large sections, or the open web)Targeted collection (specific fields such as prices, reviews, or posts)
ProcessFollows links, stores or passes raw HTML, repeats until queue is emptyParses HTML/DOM, APIs, or dynamic content to extract defined fields
OutputURLs, raw HTML, unstructured page dataClean datasets (JSON, CSV, database entries, Markdown, etc.)
ToolsCrawlers like Bright Data Crawler API, Firecrawl, ScrapyScrapers like Bright Data, Firecrawl Extract, Apify, Playwright, BeautifulSoup
Resource needsNetwork-heavy and often expensive to run at scaleCPU/memory heavy for parsing, but cheaper if pages are already discovered
AnalogyLike mapping a city — recording every street and buildingLike shopping — collecting specific items from selected stores

Conclusion

Data crawling and web scraping are two core concepts underpinning most real-time data pipelines. Crawling powers data discovery and scraping brings structure to your data so you can then curate and integrate the data into your systems.

In many systems today, data crawling and web scraping are used in tandem. The crawler operates and when valuable data gets discovered, a scraper is triggered and the crawl continues. With a proper data crawling and web scraping setup, your team can implement real-time extraction and analytics to power your next application.