Web Crawlers

Article Contents

    Web crawling is the process of fetching documents or resources identified by hyperlinks and recursively retrieving all referenced web pages.

    Web crawlers are used for search engine indexing purposes, but can be harmful if they target your website as they will often try to extract sensitive information like credit card numbers or passwords. Malicious web crawlers can be filtered out using bot management systems.

    For in-depth analysis, web crawlers need to be programmed using languages like C++Java etc. However, for quickly looking into websites like e-commerce stores/catalogues or product reviews they can also be scripted using high-level programming languages like Python.

    Types of web crawlers

    To make a list of web crawlers, you need to know the 3 main types of web crawlers:

    • In-house web crawlers
    • Commercial web crawlers
    • Open-source web crawlers

    In-house web crawlers are developed in-house by a company to crawl its own website for different purposes like – generating sitemaps, crawling the entire website for broken links etc.

    Commercial web crawlers are those which are commercially available and can be purchased from companies who develop such software. Some large companies might have their custom-built spiders as well for crawling websites.

    Open-source crawlers are those that are open-sourced or under some free/open license so that anybody can use them and modify them as per their needs. Though these often lack advanced features and functionalities of commercial counterparts they do provide an opportunity to look into source code and understand how these things work!

    List of common web crawlers

    In-house web crawlers

    • Applebot – crawls Apple’s website for updates, etc.
    • Googlebot – crawls Google websites (like Youtube) for indexing content for Google search engine
    • Baiduspider – crawls websites from Baidu.com

    Commercial web crawlers

    • Swiftbot – a web crawler for monitoring changes to web pages
    • SortSite – a web crawler for testing, monitoring and auditing websites

    Open-source web crawlers

    • Apache Nutch – a highly extensible and scalable open-source web crawler that can also be used to create a search engine
    • Open Search Server – a Java web crawler that can be used to create a search engine or for indexing web content

    Block Bots Effortlessly with Netacea

    Book a demo and see how Netacea autonomously prevents sophisticated automated attacks.



    Web Scraping

    Web scraping (or web harvesting or screen scraping) is the process of automatically extracting data from an online service website.

    Two-Factor Authentication

    Two-factor authentication (2FA) is an extra layer of security to help protect your accounts from hackers and cybercriminals.

    Non-Human Traffic

    Non-human traffic is the generation of online page views and clicks by automated bots, rather than human activity.

    Block Bots Effortlessly with Netacea

    Demo Netacea and see how our bot protection software autonomously prevents the most sophisticated and dynamic automated attacks across websites, apps and APIs.
    • Agentless, self managing spots up to 33x more threats
    • Automated, trusted defensive AI. Real-time detection and response
    • Invisible to attackers. Operates at the edge, deters persistent threats
    Book a Demo