< Back to previous view
Sign in


The goal of The Encyclopedia of Graphs is to become a general reference repository of collections of graphs. However, we are not alone in this world and we greatly appreciate all the initiatives for graph generation or collection. Therefore, we provided the sites where you can find more collections, especially larger families that are just too big to show here.

Graph collections

Graph generation tools

Graph generation software ranges from specific open-source tools to bundled software packages (that do not come cheap).

Graph representations

Graphs can be encoded in many ways, depending if our goal is smaller size or human readability. Here we name a few:

For collections it's best to work with graph6/sparse6 encodings as they offer smallest size in general and can be further compressed using data compression algorithms (zip, gzip, etc.). But they have a drawback of not supporting directed graphs (which can be written in digraph6 encoding). The Encyclopedia works with sparse6 format due to its higher efficiency for non-dense graphs.

Network tools

Network representations

Networks can also be encoded in many ways, depending on the functionality needed. Here we name a few:

For more info on these formats please visit the Gephi supported graph formats page. Our networks are encoded in the Pajek .net format as described in the Pajek software manual (pages 87-90).

Thank you again for visiting the Encyclopedia!

GReGAS Atlas Team