Easy Ways to Find All the Subdomains of a Domain

Easy Ways to Find All the Subdomains of a Domain
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In today’s digital era, websites are like the beating heart of any business. And just like our bodies rely on a strong backbone for support, websites depend on domains to function smoothly. Knowing how to handle domains effectively is key for anyone running a business website, developers, and those concerned about cybersecurity in our fast-paced online world.

Now, let’s talk about subdomains. Think of them as helpful signposts within a website. They point you to specific areas or pages, making navigation easier within the website’s overall framework.

What is a Subdomain?

In technical terms, a subdomain is a subsection of a larger domain that organizes and redirects specific areas or functions within a website. Structurally, subdomains are part of the main domain’s hierarchical structure. Typically, it appears as a prefix to the primary domain name. They are mainly helpful in organizing and accessing specific sections or features of a website. 

To explain with an example, let’s say there is a web address, “blog.sample.com,” “blog” is the subdomain, and “sample.com” is the main website.


Also Read: What Are Subdomains & How To Use Them?


Difference Between Subdomain and Domain

Utility in a website mainly differs when we think about the difference between a domain and a subdomain. In layman’s terms, a domain is the main address of a house, while a subdomain is a smaller section or room within that house. The domain is the unique name that identifies the website on the internet. 

Let’s see the rest below separately, 

PointsDomainSubdomain
Scope and PurposeA domain represents the main address of a website, serving as its unique identifier on the internet.A subdomain extends the primary domain, allowing for further segmentation and organization of content or services.
StructureA domain typically consists of two parts: the top-level domain (TLD), such as “.com,” “.org,” or “.net,” and the second-level domain (SLD), which is the customizable portion chosen by the website owner.A subdomain appears as a prefix to the primary domain name, forming part of its hierarchical structure. For example, in “blog.sample.com,” “blog” is the subdomain, and “sample.com” is the primary domain.
FunctionalityThe primary domain serves as the overarching umbrella for the entire website, representing its main identity.Subdomains provide a means to create distinct sections or functionalities within the site, such as “blog.sample.com” for the blog section, “shop.sample.com” for e-commerce, or “support.sample.com” for customer support.
OrganizationDomains establish a website’s overall identity and branding, often reflecting the business name or purpose.Subdomains facilitate the organization and categorization of content or services, enabling easier navigation and management of complex websites.

Why Do Finding Subdomains Matter?

Discovering subdomains isn’t just about technical exercise. It’s really important for managing websites, keeping them safe from cyber threats, and ensuring they’re visible and accessible online. Here are several reasons why finding subdomains matters:

Enhanced Security Posture

Subdomains could be an easy spot for hackers to sneak into a website, like finding an unlocked window or door. Finding those and locking them down properly makes the website safer, reducing the chances of hackers stealing your data or causing trouble at any point.

Comprehensive Asset Inventory

With the time and nature of the business progression, websites often evolve over time; you may add new sections or features, creating new subdomains. 

Keeping track of all these subdomains gives website owners a complete list of their online assets. This helps them manage everything more effectively and closely monitor what’s going on with their website.

Improved SEO Performance

Subdomains impact a website’s search engine ranking and user experience. Knowing all subdomains helps owners optimize each section for relevant keywords, improving overall search engine visibility.

Effective Resource Allocation

Large companies manage many subdomains for different departments or regions. Identifying them helps allocate resources effectively for properly supporting and optimizing each website section.

Regulatory Compliance

Some rules, like GDPR or HIPAA, say companies must control all their online assets, even subdomains. If companies find and manage all their subdomains, they follow these rules and avoid fines for not following them.

Brand Protection

Subdomains are important for keeping a brand’s image intact online. Monitoring and managing subdomains prevents anyone from using them in ways that could damage the brand’s reputation or break the rules about using their ideas.

Business Continuity

Subdomains can house important parts of a business, like services, apps, or communication methods. Ensuring all subdomains are safe means these important parts can continue working smoothly, even if there are problems elsewhere, keeping the business running without interruptions.

Finding subdomains is essential for bolstering security, maintaining regulatory compliance, optimizing SEO performance, and ensuring effective resource allocation and brand protection. 

Website owners can proactively address vulnerabilities, streamline operations, and enhance their online presence and resilience by conducting thorough subdomain reconnaissance.


Also Read: What Are Nameservers & What Does A Name Server Do?


What are the Methods to Find Subdomains?

Uncovering subdomains involves various techniques and tools, from manual to automated solutions. Here, we’ll explore the different approaches to finding subdomains:

1. Manual Methods

Use Google Command

  •  Google’s search engine indexing can reveal subdomains associated with a domain.
  •  Utilize the site: operator in Google search, followed by the domain name, to display indexed subdomains. For example, we are taking ‘site:forbes.com’
site forbes.com


Also Read: Should I Buy Multiple Domain Names And Extensions?


2. Automated Tools

Automated tools offer efficiency and scalability in subdomain discovery, allowing users to uncover a comprehensive list of subdomains with minimal effort. 

Here are twelve tools, along with instructions on how to use them:

Sublist3r

  •  Sublist3r is a Python-based tool that leverages search engines to enumerate subdomains.

To install that tool into your Linux server, follow the process below:

  •  For downloading, enter the following command.
wget https://github.com/aboul3la/Sublist3r/archive/master.zip
  •  Once it is done, you have to extract the downloaded file.
unzip master.zip
  •  Add the following command to find the subdomains.
python sublist3r.py -d example.com

This command will generate a list of subdomains for the domain.


Also Read: How Do You Transfer A Domain Name


DNSDumpster

  •  DNSDumpster is an online tool that retrieves subdomain information from DNS data.
  •  Access the website and enter the domain name to generate a list of subdomains.
generate a list of subdomains

Virustotal

  •  Virustotal, primarily known for malware scanning, also offers subdomain search functionality. 
  •  You just need to visit the website & enter your domain in the ‘Search’ section. 
enter your domain in the ‘Search’ section
  •  Visit the Virustotal website, enter the domain name, and navigate to the ‘Subdomains’ tab.
navigate to the ‘Subdomains’ tab


Also Read: Why Should You Renew Your Domain Before It Expires?


Amass

  •  Amass is an open-source tool for network mapping and subdomain discovery.
  •  You need to install it by entering the following command.
snap install amass
  •  To find the subdomains, execute the following command 
amass enum -d example.com

Hence, this command will generate a list of subdomains for the domain.

Censys

  •  Censys provides a robust search engine for internet-wide network data, including subdomains.
  •  Visit the Censys website, enter the domain name, and explore the search results.
Visit the Censys website

Knockpy

  •  Knockpy is a Python-based subdomain discovery tool that utilizes wordlists.
  •  Install and run Knockpy using the following command.
git clone https://github.com/guelfoweb/knock.gitcd knock pip install -r requirements.txt
  •  Enter the following command to find the subdomains.
knockpy -d example.com


Also Read: Is Investing In Domain Name Privacy Protection Necessary?


Conclusion

In conclusion, there are different ways and tools to find subdomains, from simple searches like Google or NsLookup to more automated options like Sublist3r, DNSDumpster, and Amass. By using these tools well, website owners and cybersecurity folks can make their websites safer, improve how they show up in online searches, and understand their online assets better. 

Whether done by hand or with automated tools, checking out subdomains is important for keeping a strong online presence and staying safe from potential threats.


Yash-Vasaiya

An Information Technology Engineering Graduate with over 5 years of experience in Content Marketing. I excel in crafting engaging content across various technologies and am skilled in devising promotional strategies that lead to remarkable conversions.

Philosophy: Embracing growth through collaboration. I believe in cultivating a team where each member is a leader, fostering an environment where skills and knowledge shine collectively.

Continuous Learner: I am not just into content; I actively seek opportunities to delve into new fields, exploring the frontier of Artificial Intelligence (AI) to elevate content operations.

Tech Savvy: With a strong command of various technologies, I specialize in Microsoft Technologies and excel in AI-supported process building. Certified as a professional, I combine expertise with a flair for AI and Prompt engineering.