tldextract 5.3.1
Accurately separates a URL's subdomain, domain, and public suffix, using the Public Suffix List (PSL). By default, this includes the public ICANN TLDs and their exceptions. You can optionally support the Public Suffix List's private domains as well.
Requires Python: >=3.10
Keywords: tld, domain, subdomain, url, parse, extract, urlparse, urlsplit, public, suffix, list, publicsuffix, publicsuffixlist

# tldextract [![PyPI version](https://badge.fury.io/py/tldextract.svg)](https://badge.fury.io/py/tldextract) [![Build Status](https://github.com/john-kurkowski/tldextract/actions/workflows/ci.yml/badge.svg)](https://github.com/john-kurkowski/tldextract/actions/workflows/ci.yml)

`tldextract` accurately separates a URL's subdomain, domain, and public suffix,
using [the Public Suffix List (PSL)](https://publicsuffix.org).

**Why?** Naive URL parsing like splitting on dots fails for domains like
`forums.bbc.co.uk` (gives "co" instead of "bbc"). `tldextract` handles the edge
cases, so you don't have to.

## Quick Start

```python
>>> import tldextract

>>> tldextract.extract('http://forums.news.cnn.com/')
ExtractResult(subdomain='forums.news', domain='cnn', suffix='com', is_private=False)

>>> tldextract.extract('http://forums.bbc.co.uk/')
ExtractResult(subdomain='forums', domain='bbc', suffix='co.uk', is_private=False)

>>> # Access the parts you need
>>> ext = tldextract.extract('http://forums.bbc.co.uk')
>>> ext.domain
'bbc'
>>> ext.top_domain_under_public_suffix
'bbc.co.uk'
>>> ext.fqdn
'forums.bbc.co.uk'
```

## Install

```zsh
pip install tldextract
```

## How-to Guides

### How to disable HTTP suffix list fetching for production

```python
no_fetch_extract = tldextract.TLDExtract(suffix_list_urls=())
no_fetch_extract('http://www.google.com')
```

### How to set a custom cache location

Via environment variable:

```python
export TLDEXTRACT_CACHE="/path/to/cache"
```

Or in code:

```python
custom_cache_extract = tldextract.TLDExtract(cache_dir='/path/to/cache/')
```

### How to update TLD definitions

Command line:

```zsh
tldextract --update
```

Or delete the cache folder:

```zsh
rm -rf $HOME/.cache/python-tldextract
```

### How to treat private domains as suffixes

```python
extract = tldextract.TLDExtract(include_psl_private_domains=True)
extract('waiterrant.blogspot.com')
# ExtractResult(subdomain='', domain='waiterrant', suffix='blogspot.com', is_private=True)
```

### How to use a local suffix list

```python
extract = tldextract.TLDExtract(
    suffix_list_urls=["file:///path/to/your/list.dat"],
    cache_dir='/path/to/cache/',
    fallback_to_snapshot=False)
```

### How to use a remote suffix list

```python
extract = tldextract.TLDExtract(
    suffix_list_urls=["https://myserver.com/suffix-list.dat"])
```

### How to add extra suffixes

```python
extract = tldextract.TLDExtract(
    extra_suffixes=["foo", "bar.baz"])
```

### How to validate URLs before extraction

```python
from urllib.parse import urlsplit

split_url = urlsplit("https://example.com:8080/path")
result = tldextract.extract_urllib(split_url)
```

## Command Line

```zsh
$ tldextract http://forums.bbc.co.uk
forums bbc co.uk

$ tldextract --update  # Update cached suffix list
$ tldextract --help    # See all options
```

## Understanding Domain Parsing

### Public Suffix List

`tldextract` uses the [Public Suffix List](https://publicsuffix.org), a
community-maintained list of domain suffixes. The PSL contains both:

- **Public suffixes**: Where anyone can register a domain (`.com`, `.co.uk`,
  `.org.kg`)
- **Private suffixes**: Operated by companies for customer subdomains
  (`blogspot.com`, `github.io`)

Web browsers use this same list for security decisions like cookie scoping.

### Suffix vs. TLD

While `.com` is a top-level domain (TLD), many suffixes like `.co.uk` are
technically second-level. The PSL uses "public suffix" to cover both.

### Default behavior with private domains

By default, `tldextract` treats private suffixes as regular domains:

```python
>>> tldextract.extract('waiterrant.blogspot.com')
ExtractResult(subdomain='waiterrant', domain='blogspot', suffix='com', is_private=False)
```

To treat them as suffixes instead, see
[How to treat private domains as suffixes](#how-to-treat-private-domains-as-suffixes).

### Caching behavior

By default, `tldextract` fetches the latest Public Suffix List on first use and
caches it indefinitely in `$HOME/.cache/python-tldextract`.

### URL validation

`tldextract` accepts any string and is very lenient. It prioritizes ease of use
over strict validation, extracting domains from any string, even partial URLs or
non-URLs.

## FAQ

### Can you add/remove suffix \_\_\_\_?

`tldextract` doesn't maintain the suffix list. Submit changes to
[the Public Suffix List](https://publicsuffix.org/submit/).

Meanwhile, use the `extra_suffixes` parameter, or fork the PSL and pass it to
this library with the `suffix_list_urls` parameter.

### My suffix is in the PSL but not extracted correctly

Check if it's in the "PRIVATE" section. See
[How to treat private domains as suffixes](#how-to-treat-private-domains-as-suffixes).

### Why does it parse invalid URLs?

See [URL validation](#url-validation) and
[How to validate URLs before extraction](#how-to-validate-urls-before-extraction).

## Contribute

### Setting up

1. `git clone` this repository.
2. Change into the new directory.
3. `pip install --upgrade --editable '.[testing]'`

### Running tests

```zsh
tox --parallel       # Test all Python versions
tox -e py311         # Test specific Python version
ruff format .        # Format code
```

## History

This package started from a
[StackOverflow answer](http://stackoverflow.com/questions/569137/how-to-get-domain-name-from-url/569219#569219)
about regex-based domain extraction. The regex approach fails for many domains,
so this library switched to the Public Suffix List for accuracy.