Most graph theorists will agree that among the vast number of graphs that exist there are only a few that can be considered really *interesting*.

It is the aim of this House of Graphs project to find a workable definition of 'interesting' and provide a searchable database of graphs that conform to this definition. We also allow users to add additional graphs which they find interesting. In order to avoid abuse, only registered users can add new graphs.

We would also like to serve as a repository for lists of graphs (which can be downloaded in several formats) and graph generators.

These lists of graphs and generators can be found in the graph meta-directory.

If you use House of Graphs in your research, you can cite it as:

G. Brinkmann, K. Coolsaet, J. Goedgebeur, H. Mélot, House of Graphs: a database of interesting graphs, Discrete Applied Mathematics, 161(1-2):311-314, 2013 (DOI). Available at http://hog.grinvin.org

The past year we have completely rebuilt the House of Graphs website using more modern frameworks as several of the frameworks used in the current House of Graphs were outdated and approaching an end of life status (note that we started developing HoG in 2010). We have also added several new features (e.g. the possibility to edit graph drawings and support for storing multiple drawings per graph) and several other updates which should improve the user experience.

The website is still under development, but we hope to release it soon. In the meantime you can already try the beta version of the new website at http://house.ugent.be

We will migrate the entire database of the current House of Graphs to the new website when we launch the new website, so all graphs, comments, accounts, etc. will be preserved.

- 2021-09-16: Added list of 3-connected planar self-dual graphs to the meta-directory.
- 2021-09-07: Added list of minimal Cayley graphs to the meta-directory.
- 2020-07-09: It is now possible to search for a graph with a given graph6 string (rather than having to upload it from a file).
- 2019-11-22: Added list of perihamiltonian graphs to the meta-directory.
- 2019-09-17: Added list of snarks with minimal circular flow number to the meta-directory.
- 2019-08-08: Added list of regular nut graphs to the meta-directory.
- 2019-03-28: Added list of permutation snarks to the meta-directory.
- 2019-03-18: Added list of cographs to the meta-directory.
- 2018-12-12: Added list of uniquely hamiltonian graphs to the meta-directory.
- 2018-08-31: Added list of snarks with oddness 4 to the meta-directory.
- 2018-05-31: Added support to search for a graph with a specific HoG graph id.
- 2018-05-29: Added the invariants circumference, density and planar.
- 2018-05-28: It is now possible to view the 10 most recently added graphs.
- 2018-03-22: Added list of snarks with circular flow number 5 to the meta-directory.
- 2017-11-17: Added list of triangle-free k-chromatic graphs to the meta-directory.
- 2017-10-16: Added list of platypus graphs to the meta-directory.
- 2017-06-08: Added list of nut graphs to the meta-directory.