UTM Campaign Parameter Builder
About Subdomain Extractor
The Subdomain Extractor & Host Hierarchy Parser separates subdomains (e.g. `api`, `auth.staging`), Second-Level Domains (SLD), and Top-Level Domains (TLD) from complex URLs using Public Suffix List (PSL) rules.
How to Use Subdomain Extractor
Step 1
Paste one or more URLs into the extractor.
Step 2
Inspect the parsed hierarchy table (Subdomain, Domain, Suffix).
Step 3
Click "Export CSV" or copy unique subdomains.
Practical Use Cases for Subdomain Extractor
Subdomain Enumeration & Security Asset Mapping
Extract and isolate all unique subdomains from web server access logs and certificate transparency monitoring feeds.
Multi-Tenant SaaS Architecture Routing
Parse tenant subdomains (e.g. `acme.app.com` $\rightarrow$ tenant: `acme`) for custom application routing rules.
Input & Output Examples
Parsing Complex Multi-Level Domain
URL: "https://api.v2.staging.example.co.uk/users"
Subdomain: "api.v2.staging" | SLD: "example" | TLD: "co.uk" | Root Domain: "example.co.uk"
Key Features & Performance
- ✓Extracts Subdomain, Apex Root Domain, and Top-Level Domain (TLD).
- ✓Recognizes multi-part country code TLDs (`.co.uk`, `.com.au`, `.gov.in`) via Public Suffix List logic.
- ✓Batch processing: parse thousands of URLs simultaneously.
- ✓100% Client-Side memory execution.
- ✓1-Click Export CSV hierarchy breakdown.
Key Terminology & Definitions
Public Suffix List (PSL)
A community-maintained initiative listing all domain suffixes under which internet users can directly register names (such as `.co.uk` and `.github.io`).
Second-Level Domain (SLD)
The domain name registered immediately to the left of the public suffix (e.g. `google` in `google.com`).