We are pleased to announce a new release of host-level and domain-level web graphs based on the crawls of February/March, April and May 2021. Additional information about the data formats, the processing pipeline, our objectives, and credits can be found in the announcements of prior webgraph releases. You may also visit the projects cc-webgraph and cc-pyspark which include all scripts and tools required to construct the graphs. Instructions to explore the graphs in the webgraph format are given in our collection of webgraph notebooks.
What's new?
The host-level graph now includes all hosts visited by the crawler even if there is no link pointing to the host and all visited URLs of a host failed (HTTP 404 and other error codes) or the host's robots.txt does not allow crawling. Note that the links leading to these hosts may have been found in a prior crawl, not in one of the 3 crawls used to build this web graph.
Host-level graph
The graph consists of 515 million nodes and 2.82 billion edges. Both hyperlinks and HTTP redirects and link headers are used as edges to span up the graph. All types of links are included, including pure "technical" ones pointing to images, JavaScript libraries, web fonts, etc. However, only host names with a valid IANA TLD are used. Consequently, URLs with an IP address as host component are not taken into account for building the host-level graph.
There are 452 million dangling nodes (87.9%) and the largest strongly connected component contains 45.2 million (8.8%) nodes. Dangling nodes stem from
- hosts that have not been crawled, yet are pointed to from a link on a crawled page
- hosts without any links pointing to a different host name
- or hosts which did only return an error page (eg. HTTP 404)
Host names in the graph are in reverse domain name notation and a leading www. is stripped: www.subdomain.example.com becomes com.example.subdomain. You can download the graph and the ranks of all 515 million hosts from AWS S3 on the path s3://commoncrawl/projects/hyperlinkgraph/cc-main-2021-feb-apr-may/host/. Alternatively, you can use https://data.commoncrawl.org/projects/hyperlinkgraph/cc-main-2021-feb-apr-may/host/ as prefix to access the files from everywhere.
Please note that the text representation of the host-level graph is shipped in 72 gzip-compressed files listed in two path listings - one for the nodes (vertices), one for the edges (arcs). First, download the paths listing and decompress it using "gzip". By adding the prefix s3://commoncrawl/ or https://data.commoncrawl.org/ to each line in the path listing you get the list of URLs to download the entire graph.
Download files of the Common Crawl Feb/Apr/May 2021 host-level Webgraph
Domain-level graph
The domain graph is built by aggregating the host graph on the level of pay-level domains (PLDs) based on the public suffix list maintained on publicsuffix.org.
The domain-level graph has 88 million nodes and 1.58 billion edges. 50% or 44 million nodes are dangling nodes, the largest strongly connected component covers 34 million or 39% of the nodes.
All files related to the domain graph are available on AWS S3 under s3://commoncrawl/projects/hyperlinkgraph/cc-main-2021-feb-apr-may/domain/ resp. https://data.commoncrawl.org/projects/hyperlinkgraph/cc-main-2021-feb-apr-may/domain/.
Download files of the Common Crawl Feb/Apr/May 2021 domain-level Webgraph
Credits
Thanks to the authors of the WebGraph framework, whose software made the computation of graph properties and ranks possible. We hope the data will be useful for you to do any kind of research on ranking, graph analysis, link spam detection, etc. Let us know about your results via Common Crawl's Google Group!
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