How to Avoid Web Scraper IP Blocking? The Expert Guide

Hi there!

As an expert in proxies and web scraping, let me walk you through how websites block scrapers with IP tracking, and more importantly – how you can avoid getting caught!

Blocking scrapers through IP analysis is a common tactic, but with the right strategies you can keep your scrapers running smoothly.

In this comprehensive guide, we‘ll cover:

How websites identify and blacklist scraper IPs
All the techniques used to track and profile IPs
IP address details like structure and metadata
Advanced circumvention tactics and tools
Best practices to avoid blocks for your scrapers

By the end, you‘ll be an IP ninja ready to scrape without a hitch!

How Websites Track and Detect Scrapers Through IPs

Websites want to stop scrapers from slurping up their data. So they employ advanced techniques to track and identify scraper IPs by building "trust scores."

There are two key components:

1. Monitoring and Profiling IP Addresses

Websites keep extensive logs of all connection IP addresses and monitor them for patterns that signify scrapers:

Frequent connections from the same IP
Too many requests per IP over time
IPs from suspicious blocks known for abuse

In many cases, if an IP connects more than 100 times a day or 1,000 times a month it‘s considered suspicious.

They also analyze IP relationships – if multiple IPs from the same sub-network behave alike, guilt by association applies and all get lower trust.

According to Minerva Labs research, over 70% of sites now profile IP behavior to detect scraping.

2. Cross-Referencing Contextual IP Metadata

Websites check each connecting IP against various databases to fetch context:

Ownership details like host type (datacenter, residential ISP etc.)
Location and geography
Hosting provider information
Known malicious IP lists

This allows them to separate rogue scraper bots from real visitors.

Over 80% of websites supplement their logs with IP metadata from sources like WHOIS, MaxMind, and threat intel feeds according to Imperva.

They feed all this data into algorithms that calculate "IP reputation" scores to allow or block each connection.

Low rep IPs suspected of scraping get challenged with CAPTCHAs or blocked outright. While high rep IPs get easy access.

Now let‘s take a deep dive into IP address details to understand exactly how these techniques work.

IP Address Versions, Structure and Metadata

To evade IP blocks, you need expertise on IP address composition and surrounding metadata.

IP Address Versions: IPv4 vs IPv6

There are two key IP address versions:

IPv4:

32 bit address structure
Around 4 billion possible addresses
Most widely adopted version
Running out of new address space

Fun fact: Nigeria and Philippines exhausted their IPv4 allocations in 2022!

IPv6:

New 128 bit address structure
Offers over 340 trillion possible IPs!
Very low global adoption so far
No risk of address shortage

For web scraping, IPv4 is currently best as IPv6 allows easier anonymity due to high availability. So sites scrutinize IPv6 traffic more to compensate.

According to Google‘s IPv6 statistics, only around 30% of the internet uses IPv6 so far.

IP Address Structure and Significance

IPv4 addresses are made up of 4 octets separated by dots, for example: 172.217.4.46

The last two octets are most revealing for tracking:

The third octet identifies the internal sub-network
The fourth octet identifies the host/connection on that sub-network

So in 172.217.4.46:

172.217 is the overall network operated by the ISP/host
4 signifies the internal sub-network
46 identifies the specific host connecting from that sub-network

Sub-network IDs often tie to regions while host IDs represent individual clients.

According to Rapid7 analysis, 87% of IPs can be reliably mapped to a city using the sub-network segment.

IP WHOIS Records and Metadata

To supplement what the IP itself reveals, websites cross-reference public WHOIS records to get context like:

Registered owner name and contact info
Hosting provider or ISP details
Connection type (datacenter, residential etc)
Geographic location

For example, here‘s the WHOIS data for a residential IP:

IP:            192.168.10.56
ASN:           AS8912
ISP:           Comcast Cable 
Organization:  Residential Customer
Location:      Florida, United States

And a data center IP:

IP:             13.27.231.21  
ASN:            AS9223
ISP:            Amazon Technologies Inc.
Organization:   Amazon.com, Inc.
Location:       Boardman, Oregon, United States

You can instantly see how the organization type, ISP name, and other details reveal the IP type.

Over 90% of websites pass IPs through WHOIS checks according to Imperva.

How Websites Use IP Tracking To Identify & Block Scrapers

Armed with IP structure insights and metadata context, let‘s see how websites leverage them to stop scrapers:

Tracking and Profiling IP Activity

As mentioned earlier, websites log and monitor IP activity for any signals of automation:

Unnaturally high connections from one IP
Too many IPs from the same subnet
Barrages of requests during odd hours

For example, according to Imperva, if a website sees an IP making over 380 requests an hour, it‘s almost certainly a scraper.

IP clusters are also telling – hundreds of IPs from the same provider attacking simultaneously signals an orchestrated scraping effort.

Some key IP reputation scoring factors according to Minerva‘s research:

Requests per IP per hour
Concurrent IP sessions
Shared subnets with other high-activity IPs
WHOIS labels like ISP, host type etc.

With tight enough thresholds, IPs running scalable scrapers can be flagged within their first session.

Leveraging IP Metadata to Separate Scrapers

Websites cross-check IPs against various databases to fetch context:

IP Geolocation databases like MaxMind map IPs to geographic coordinates. Scrapers often geo-locate suspiciously far from actual users.
IP Registration databases like WHOIS reveal the owning organization. Scrapers tend to use providers specialized in hosting bots and proxies.
Threat intelligence feeds maintain IP blocklists known for abuse and cybercrime. Scrapers are drawn to cheap disturbed IPs which often end up on these lists.
IP Type databases segment IPs into categories like data center, residential, mobile etc. Scrapers favor data center IPs.

For example, according to Voxility, the MaxMind GeoIP database can identify the country of an IP with 99.8% accuracy.

With metadata like this, separating rogue scrapers from real visitors becomes easy.

Advanced Tracking Tactics

In addition to IP logs and metadata, some sites use other cunning techniques:

Browser fingerprinting – Combining IP profile data with browser fingerprints makes scrapers using automation frameworks obvious. Real users have much more diverse fingerprints.
Behavioral analysis – Sites profile visitor actions onsite to detect scrapes. Bots exhibit very systematic flows compared to humans.
Mouse movement tracking – By recording mouse movements, sites can identify scrapers mimicking user actions via automation. Natural unpredictable human movements are hard to fake at scale.
Network traffic patterns – The sequence of packets and data shapes overall traffic patterns. Scrapers exhibit more systematic flows compared to serendipitous human browsing.

These supplement IP tracking to make scraper detection even more precise.

How Web Scrapers Can Defeat IP Blocks

Now that you understand how sites block IP addresses, let‘s discuss proven tactics to avoid and bypass IP blocks so you can scrape freely.

Use Proxies and Proxy Rotation

Proxies allow you to route requests through external IP addresses so you don‘t directly connect from your own IPs. This prevents patterns that can betray automation.

Residential proxy services work best as their IPs match real home users both in structure and metadata.

The key is frequently rotating different proxies so you don‘t reuse the same IPs excessively.

Tools like ScraperAPI and Oxylabs make proxy automation easy.

Prioritize Trusted Proxy Providers

Not all proxy sellers are equal. Stick to reputable vendors known for reliable uptime, connection quality, and fully anonymous IPs.

Consumer proxy services often oversell unreliable IPs leading to blocks. Avoid cheap proxies.

Search for "backconnect residential proxies" to find vendors catering to scrapers.

Diversify Proxy Locations

Rotate proxies across different countries, subnets, ASNs, and providers. Variety beats quantity for avoiding blocks.

Scrapers often connect tunnels through one subnet, making identification easy. Blend residential IPs across multiple geographies and providers.

Tools like Luminati and GeoSurf simplify proxy orchestration.

Limit Requests Per Proxy

Don‘t overuse individual proxies. Throttle request volume and space out scrapes to keep activity human-like.

Let IPs rest between sessions before reuse. According to Apify, proxies averaged ~1000 requests over 2 days safely avoided blocks.

Use Specialized Scraping Tools

Services like ScrapingBee and ScrapeHero provide turnkey scraping solutions that automate proxy rotation and other anti-blocking defenses for you.

Their infrastructure and smart tooling prevent IP blocks so you can focus on data.

Avoid Known Bad IP Blocks

Tools like Badips.com share lists of IP blocks identified for scraping abuse.

Check proxies against these before use to avoid those already flagged. Some proxies guarantee unused virgin IPs.

Let‘s now see how expert proxies service ScrapFly automates IP evasion.

IP Rotation Automation with ScrapFly

ScrapFly offers an intelligent proxy API that handles IP cycling automatically.

It analyzes websites‘ defenses dynamically to select the optimal undetected IPs from a pool of 190+ million for each request.

This enables high-performance scraping resilient to even reactive blocking.

ScrapFly also defeats other anti-scraping tactics like browser fingerprinting, rate limiting, CAPTCHAs and more. Plus, it supports JS rendering.

The API abstracts away all IP management and anti-blocking complexity, keeping your scrapers smooth and uninterrupted.

Try ScrapFly free today to effortlessly scrape any site worry-free!

Now let‘s cover some common IP blocking FAQs:

FAQs About IP Blocking and Web Scraping

Let‘s wrap up by answering some frequent questions about using IPs to avoid blocks:

What proxy type is best for web scraping?

Residential proxies are ideal for scraping as their IP characteristics precisely match end users. Some mobile IP providers also work well.

Avoid data center IPs as those clearly identify automation tools.

Which proxy locations are best for web scraping?

SAME GEOGRAPHY AS TARGET WEBSITE works best to appear like real visitors.

But residential proxies in US and EU have higher general trust as they derive from internet-mature regions with better IP practices.

How many proxies do I need to prevent IP blocks?

Quality beats quantity. Even a modest pool of diverse residential IPs from different providers, regions, countries and subnets is enough.

Often sites block specific IPs, not full providers. So diversity protects you even if some specific IPs get flagged.

How frequently should I rotate proxies?

There aren‘t fixed rules, but every 100-500 requests per proxy is a safe range for rotation. Pay attention to website behavior.

Let IPs rest a few days between reuse. Tools like ScrapeHero automate rotation dynamically for you.

Key Takeaways: Overcoming IP Blocks

Let‘s recap what we‘ve covered:

Websites monitor IP activity and metadata to profile visitors and identify scrapers
IP reputation scores separate real users from bots based on history and context
Avoid blocks using residential proxies from diverse sources, regions and subnets
Rotate IPs frequently and use specialized tools to automate proxy orchestration
With the right strategy, you can scrape any site without being IP blocked!

I hope this guide has armed you with in-depth knowledge to keep your web scrapers undetectable.

Wishing you happy hassle-free scraping ahead! Don‘t hesitate to reach out if you need any more tips.