# publicsuffix/list

The Public Suffix List

Repository: https://github.com/publicsuffix/list
Canonical: https://ross.abutalabs.com/products/list
Homepage: https://publicsuffix.org/
Language: Go
License: MPL-2.0
License Family: copyleft
Last push: 2026-08-19T19:18:36+00:00

## Health v2 (maintenance only)
Score: 76/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 98, release rhythm 35, longevity 100
- inputs: {"age_days": 4124, "days_push": 14, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2921, forks 1885 (observed 2026-08-28T04:07:30.209813+00:00)

## What it is
The Public Suffix List is a community-maintained dataset of all known public internet domain suffixes such as com, co.uk, and pvt.k12.ma.us. It is used by browsers and other software to determine registrable domains, prevent privacy-damaging supercookies, and correctly display domain names.

## Use cases
- determine the registrable domain of a url
- prevent cookies being set for public suffixes
- highlight the important part of a domain in a ui
- validate domain ownership for certificate issuance
- parse etld+1 from hostnames
- group browser history by site

## When to choose
- you need accurate eTLD+1 extraction across all TLDs
- you are building a browser, cookie jar, or security tool that must respect public suffix boundaries
- you need a widely adopted, community-maintained source of truth for domain suffixes

## When to avoid
- you just need a simple regex for common TLDs and can tolerate edge-case errors
- you want to register subdomains on a hosting platform like Cloudflare - the list is not a workaround
- you need a live DNS lookup service rather than a static list

## Facets
- artifact type: dataset
- maturity: active
- function: security, networking, parser
- domain: networking, security, web-development, privacy
- platform: cross-platform
- tags: public-suffix-list, domain-names, dns, cookies, mozilla

## Member repositories
- publicsuffix/list (main) score 76

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:07:30.209813+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T07:33:47.371806+00:00, confidence not recorded.
  - readme: https://github.com/publicsuffix/list (fetched 2026-08-28T04:07:30.209813+00:00, sha 8cfd3c27e4f2)
  - homepage: https://publicsuffix.org/ (fetched 2026-08-29T09:49:03.075408+00:00, sha a480e1e462e7)
- Data as of 2026-08-30T08:39:29.467469+00:00.