Extract Domains Now

Step 1 — Choose input method

💡 Quick load a sample to see how it works:

📁

Click to upload or drag & drop

TXT · CSV · HTML · JSON · XML · LOG · MD (Max 20MB)

Step 2 — Configure extraction

Source Type

Plain text (mixed)

URL list only

Email addresses

Domain Mode

Remove duplicates

Keep subdomains

Registrable only

TLD Filter

Extras

Also extract emails

Sort by:

Domain Level

Step 3 — Extract

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Root Domain ExtractorForce-strip every subdomain to reveal the registrable (root) domain. Public Suffix List aware — correctly handles .co.uk, .github.io, .appspot.com.

What Is a Root (Registrable) Domain? 🚀 Extract now

The registrable domain is the shortest domain name you could actually purchase from a registrar. For a hostname like api.blog.example.co.uk:

The full hostname is api.blog.example.co.uk
The public suffix is co.uk (a country-code second-level TLD)
The registrable domain — what you would buy from a registrar — is example.co.uk
Everything to the left (api.blog) is one or more subdomains

This tool applies the public-suffix rules automatically, so you never accidentally treat co.uk as if it were a domain.

How to Extract Root Domains 🚀 Extract now

Paste your text, URLs, or emails above (or upload a file).
Check Registrable only in the Domain Mode option card.
Click 🚀 Start Calculate.
You'll get only the registrable root domain — no subdomains, no www., no ports.

Before & After Examples 🚀 Extract now

Input hostname	Root domain
`www.example.com`	example.com
`blog.example.com`	example.com
`api.v2.staging.example.com`	example.com
`shop.example.co.uk`	example.co.uk
`a.b.c.example.com.au`	example.com.au
`user.github.io`	user.github.io (github.io is a public suffix)
`app.example.appspot.com`	example.appspot.com (appspot.com is a public suffix)

Why Root Domains Matter 🚀 Extract now

🚫 Google Disavow Files

Google's disavow tool wants root domains, one per line, prefixed with domain:. Extract root, then prepend.

📊 Aggregated Analytics

Group traffic by root domain so www, m., blog. variants roll up together.

🔒 Firewall Domain Rules

Block/allow at the root level to cover all subdomains at once.

💼 CRM Account Matching

Match leads to companies by root domain rather than exact email host.

Public Suffix List Compliance 🚀 Extract now

We use the same rule structure as Mozilla's Public Suffix List, which is the industry standard for determining what part of a domain can be "owned" versus what is a public infrastructure suffix. This means:

example.co.uk is correctly identified (not co.uk)
user.github.io stays as-is because github.io is a public suffix
Amazon S3 subdomains, Google App Engine domains, and other multi-tenant hosts are handled correctly

Related Tools 🚀 Extract now

FAQ 🚀 Extract now

What's the difference between root domain and registrable domain?

In this tool they're the same thing — both refer to the shortest domain a person could actually register (e.g. example.co.uk, not co.uk).

How is .co.uk handled?

Correctly. shop.example.co.uk reduces to example.co.uk. This works for every multi-part TLD in the Public Suffix List.

Why does user.github.io stay untouched?

Because github.io is on the Public Suffix List — it's public infrastructure for GitHub Pages. The registrable domain is user.github.io.

Root Domain Extractor