The Complete Guide to Collecting Online Data at Scale
The internet holds a vast trove of valuable data – from e-commerce product details and pricing to business leads, real estate listings, financial data, and much more. Many companies rely on web scraped data to gain business insights, inform strategy, and create new products and services.
However, collecting online data at scale comes with challenges. Websites actively try to detect and block scraping activity to protect their data and preserve server resources. This means scrapers must take steps to avoid getting their IP addresses banned when harvesting large amounts of data.
In this guide, we‘ll dive into how web scraping works, the limitations of scraping without proxies, and why rotating proxy IPs is essential for reliable data collection. We‘ll cover the best practices for stealth scraping, compare proxy options, and introduce top proxy providers trusted by professional data gathering teams.
How Web Scraping Works
At its core, web scraping involves programmatically downloading the HTML from web pages and extracting the target data into a structured format like a spreadsheet or database. Scrapers make HTTP requests just like a web browser does when a user visits a site.
Scrapers are typically built using Python libraries like Scrapy and BeautifulSoup or headless browsers like Puppeteer. They parse the HTML to find the desired data based on elements, tags, and styling. More advanced scrapers can handle JavaScript rendering, login walls, CAPTCHAs, and other challenges.
While small one-off scraping tasks can often be done manually, collecting data at scale requires automation. However, when a scraper starts rapidly crawling a site and submitting a high volume of requests, it quickly gets flagged as a bot.
Servers look for signals like high request volume, aggressive crawl rate, and unusual traffic patterns. When detected, they will start serving CAPTCHAs, blocking IP addresses, or even feeding fake data to throw off the scraper. Some sites have strict anti-bot measures that will ban an IP after just a handful of requests.
Scraping With Your Own IP Address
For collecting a small amount of public data as a one-off project, you may be able to get by using your own IP address. However, this comes with major risks and limitations.
If a site detects your scraping activity, your IP could get blacklisted and you‘ll be unable to access the site or collect any more data. Getting your company‘s or home‘s IP address banned can be a major inconvenience.
To reduce the risk of detection, you can try slowing down your request rate to mimic human behavior. But this severely limits how much data you can gather. You‘re still constrained by a single IP address that could get blocked at any time.
Some people attempt to hide their real IP address by routing their traffic through Tor or a VPN. While this provides some anonymity, these tools are not designed for the high traffic of web scraping.
Tor only has around 20,000 exit nodes, most of which are known and blocked by major websites. Using Tor for scraping can get the whole Tor network banned. VPNs also typically have a limited pool of IPs and aren‘t built to handle bot traffic.
Rotating user agents is another tactic that can help a scraper appear as a normal web browser and avoid rudimentary bot detection. But on its own, cycling through user agent strings does little to prevent getting blocked.
Using Headless Browsers for Scraping
Headless browsers like Puppeteer, Playwright, and Selenium are popular for web scraping because they can automate interaction with complex sites that heavily use JavaScript. Since they run without a visible GUI, they can efficiently scrape multiple pages at once.
However, headless browsers consume significant system resources in terms of memory and CPU usage. They are harder to scale compared to lightweight scrapers. More importantly, they still share the same fundamental flaw – using a single IP address that‘s vulnerable to getting banned.
Ultimately, there‘s no reliable way to do large-scale web scraping without using proxies. Proxies allow you to distribute your scraping requests across a pool of hundreds or thousands of IP addresses. By rotating through these IPs, you can avoid detection and bans.
Scraping with Rotating Proxies
A proxy acts as an intermediary, routing your web requests through a different IP address. When you use proxies for scraping, the target website sees the request coming from the proxy‘s IP rather than your own.
There are two main types of proxies:
Data center proxies come from cloud servers in data centers. They are fast and cheap but easier to detect as proxies since they aren‘t associated with real users or devices.
Residential proxies come from real devices on consumer internet service provider (ISP) networks. They are harder to detect and less likely to get banned, but are slower and more expensive.
To effectively hide your scraping activity, you need to spread requests across a large pool of proxies, rotating IP addresses every few requests. This makes it appear to the target site that all the traffic is coming from many different real users rather than a single scraper.
How Often to Rotate Proxy IPs
The ideal IP rotation frequency depends on the particular website, but in general it‘s best to switch to a new IP address every 1-5 requests to avoid tripping rate limits and other anti-scraping measures.
The exact rotation logic can be configured based on successful vs failed requests, CAPTCHAs, or other signals of detection. More advanced scraping systems use machine learning to adaptively adjust the request flow.
Some websites track IP reputation over time, so it‘s also good to cycle through the whole proxy pool periodically to let IP addresses "cool off" rather than reusing the same small set continuously.
Choosing high-quality proxies from reputable providers is crucial, as many free and cheap proxy lists include IPs that are already banned by major sites. Proxies should be anonymous and undetectable as coming from a data center.
Top Proxy Providers for Web Scraping
The leading proxy providers for enterprise-grade web scraping include:
Bright Data – the world‘s largest proxy network with over 72 million residential IPs
IPRoyal – a self-service residential proxy platform with flexible pricing
Proxy-Seller – a premium provider with high anonymity proxies and 24/7 customer service
SOAX – a residential proxy network that supports advanced rotation and targeting
Smartproxy – an established provider of rotating datacenter and residential proxies
Proxy-Cheap – a reliable and affordable option for residential and mobile proxies
HydraProxy – a worldwide proxy network with high success rates for sneaker/ticket botting and scraping
These providers offer large proxy pools, automatic rotation, and flexible targeting options to optimize performance and avoid detection. It‘s worth comparing plans to find the best fit for your data gathering needs and budget.
Conclusion
To reliably collect online data at scale, there‘s no way around using proxies to distribute and anonymize your requests. Techniques like Tor, VPNs, user agent spoofing, and headless browsers can help hide your identity, but they aren‘t sufficient on their own.
Utilizing a pool of rotating proxies from a reputable provider is essential for avoiding IP bans and ensuring successful large-scale scraping. The best practice is to rotate IP addresses every few requests and let them cool off between reuse.
With the right tools and proxy infrastructure, you can effectively gather the public web data your business needs while minimizing the risk of detection and disruption. It‘s worth experimenting with different proxy providers and configurations to find the optimal setup for your specific use case.
