referer-parser is a database for extracting marketing attribution data (such as search terms) from referer URLs, inspired by the ua-parser project (an equivalent library for user agent parsing).

The referer-parser project also contains multiple libraries for working with the referer-parser database in different languages.

referer-parser is a core component of Snowplow, the open-source web-scale analytics platform powered by Hadoop and Redshift.

Note that we always use the original HTTP misspelling of 'referer' (and thus 'referal') in this project - never 'referrer'.

The latest database is always available on this URL:

https://s3-eu-west-1.amazonaws.com/snowplow-hosted-assets/third-party/referer-parser/referers-latest.yml

The database is updated at most once a month. Each new version of the database is also uploaded with a timestamp:

https://s3-eu-west-1.amazonaws.com/snowplow-hosted-assets/third-party/referer-parser/referers-YYYY-MM.yml

If there is an issue with the database necessitating a re-release within the month, the corresponding files will be overwritten.

• Scala: https://github.com/snowplow-referer-parser/scala-referer-parser
• Java: https://github.com/snowplow-referer-parser/java-referer-parser
• Ruby: https://github.com/snowplow-referer-parser/ruby-referer-parser
• Python: https://github.com/snowplow-referer-parser/python-referer-parser
• NodeJS: https://github.com/snowplow-referer-parser/nodejs-referer-parser
• .NET: https://github.com/snowplow-referer-parser/dotnet-referer-parser
• PHP: https://github.com/snowplow-referer-parser/php-referer-parser
• Golang: https://github.com/snowplow-referer-parser/golang-referer-parser
• Erlang: https://github.com/silviucpp/refererparser

referer-parser identifies whether a URL is a known referer or not by checking it against the referers.yml file; the intention is that this YAML file is reusable as-is by every language-specific implementation of referer-parser.

The file is broken out into sections for the different mediums that we support:

• unknown for when we know the source, but not the medium
• email for webmail providers
• social for social media services
• search for search engines

Then within each section, we list each known provider (aka source) by name, and then which domains each provider uses. For search engines, we also list the parameters used in the search engine URL to identify the search term. For example:

Google: # Name of search engine referer
  parameters:
    - 'q' # First parameter used by Google
    - 'p' # Alternative parameter used by Google
  domains:
    - google.co.uk  # One domain used by Google
    - google.com    # Another domain used by Google
    - ...

The number of referers and the domains they use is constantly growing - we need to keep referers.yml up-to-date, and hope that the community will help!

We welcome contributions to referer-parser:

1. New search engines and other referers - if you notice a search engine, social network or other site missing from referers.yml, please fork the repo, add the missing entry and submit a pull request
2. Ports of referer-parser to other languages - we welcome ports of referer-parser to new programming languages (e.g. Lua, Go, Haskell, C)
3. Bug fixes, feature requests etc - much appreciated!

Please sign the Snowplow CLA before making pull requests.

General support for referer-parser is handled by the team at Snowplow Analytics Ltd.

You can contact the Snowplow Analytics team through any of the channels listed on their wiki.

referers.yml is based on Piwik's SearchEngines.php and Socials.php, copyright 2012 Matthieu Aubry and available under the GNU General Public License v3.