Subdomain Finder (2024)

FAQs

Is there a way to find all subdomains? ›

Subdomains aren't directly bad for SEO, but they're not always the most strategic choice.

A subdomain takeover occurs when an attacker gains control over a subdomain of a target domain. Typically, this happens when the subdomain has a canonical name (CNAME) in the Domain Name System (DNS), but no host is providing content for it.

A subdomain is a type of DNS record that adds a prefix to your domain, such as blog.mycoolnewbusiness.com. You can create a subdomain that uses an IP address by adding an A record to your DNS zone file. If you need a subdomain that connects to another domain name, you'll need to add a CNAME record instead.

To identify DNS entries within your organization that might be dangling, use Microsoft's GitHub-hosted PowerShell tools "Get-DanglingDnsRecords". This tool helps Azure customers list all domains with a CNAME associated to an existing Azure resource that was created on their subscriptions or tenants.

Yes. Google can penalize a website for having duplicate content across multiple domains (subdomains). If a website is found to have the same content across multiple domains, it could be seen as an attempt to manipulate search engine rankings.

However, Google treats subdomains as separate sites.

While “blog.example.com” and “example.com” may share a root domain, Googlebot will view them as distinct domains and crawl and index them accordingly.

Each domain name can have up to 500 subdomains. You can also add multiple levels of subdomains, such as info.blog.yoursite.com. A subdomain can be up to 255 characters long, but if you have multiple levels in your subdomain, each level can only be 63 characters long.

Subdomain takeover can have severe legal implications, as attackers may engage in illegal activities or host malicious content on compromised subdomains. It's crucial to report any such incidents to law enforcement authorities and take immediate steps to mitigate the risks to protect your reputation and users.

Does https hide subdomains? ›

While HTTPS encrypts the entire HTTP request and response, the DNS resolution and connection setup can reveal other information, such as the full domain or subdomain and the originating IP address, as shown above. Additionally, attackers can still analyze encrypted HTTPS traffic for “side channel” information.

Subdomain takeover is essentially DNS spoofing for a specific domain across the internet, allowing attackers to set A records for a domain, leading browsers to display content from the attacker's server. This transparency in browsers makes domains prone to phishing.

Use an A record if you manage which IP addresses are assigned to a particular machine, or if the IP are fixed (this is the most common case). Use a CNAME record if you want to alias one name to another name, and you don't need other records (such as MX records for emails) for the same name.

A subdomain only inherits the DMARC policy of the top-level domain if it does not have a DMARC record itself. This means that even if the top-level domain has "p=" or "sp=" tags they do not matter.

SSL certificate is a must online security for any online business. SSL certificates can be of many types including single domain SSL, multi domain SSL, wildcard SSL, etc. SSL certificates can secure main domains, subdomains, and multi-level domains.

If Google does not come across links to your subdomain when it's crawling your site or another site, then it won't be able to find your subdomain and thus won't index it. The only exceptions to this would be if: You submit the XML sitemap for your subdomain to Google via Google Search Console.

A domain can have up to 500 subdomains. You can create multiple levels of subdomains such as store.product.yoursite.com, test.forum.yoursite.com, etc. Each subdomain can be up to 255 characters long, but for multi level subdomains, each level can only be 63 characters long.

DNS subdomain limits

Each label (or subdomain block) can contain between 2 and 63 characters, with a limit of 127 DNS subdomains.

A subdomain, on the other hand, is another part of the URL structure that goes before the domain name. As its main purpose is for site organization, your website can work fine without it. For instance, you can set your website address as http://website.com.