These are traffic rankings up to 1m from four different sources of traffic ranking providers. The lower the number the more traffic the site gets in general. We provide all four because they are all very different.
Tranco
Tranco's rank is based on an amalgamation of Alexa, Umbrella and Majestic, more information can be found here -
https://tranco-list.eu.
Majestic
Majestic is a rank based on the most referring subnets. More information here
https://majestic.com/reports/majestic-million. Note we have removed subdomains from this list - i.e. docs.google.com isn't counted and we remove that site from the list, lowering the numbers for sites below it.
Umbrella
Umbrella is based on net sum DNS queries across the globe. More information
https://umbrella.cisco.com/blog/2016/12/14/cisco-umbrella-1-million/.
BuiltWith also provides Google, Cloudflare and Page Rank. These rankings are stored as technologies and extend beyond 1 million sites.