Domain / host extractor
Given a list of URLs, output one of: every full hostname, just the eTLD+1 (the registrable domain — news.bbc.co.uk → bbc.co.uk), or the second-level "label" (bbc). Uses the Public Suffix List bundled in-browser.
How to use
- Paste your URL list.
- Pick Output — Full hostname, eTLD+1, Subdomain only, Label.
- The result table shows the chosen field per URL, deduplicated.
- Group by dropdown counts URLs per host or per eTLD+1.
Why eTLD+1 matters
Always extract eTLD+1 (not just "last two labels") for analytics — otherwise news.bbc.co.uk and sport.bbc.co.uk will count as different "domains" if you naively take the last two labels (co.uk). The Public Suffix List knows that co.uk is a public suffix, so the registrable domain is bbc.co.uk.
FAQ
What's the Public Suffix List?
A community-maintained list of "effective TLDs" — domains under which the public can register names. It's what tells parsers that co.uk, com.au, and github.io are all public suffixes. Updated regularly; the bundled copy is current as of build time.
What if a URL has no host (mailto:, tel:)?
It's skipped — extraction works only for hierarchical URLs with a host component.
Is "subdomain only" what I want?
For news.bbc.co.uk it returns news — the bit before the registrable domain. Empty if there's no subdomain.
Why is the loading message visible?
The PSL data is loaded lazily from a CDN once (and cached). After the first load it's instant.