Graphs have a wide field of application, e.g., in mathematics, computer science, chemistry, or physics.

"Free graph theory software" is a scientific graph theory tool to construct, analyse, and visualise graphs for science and teaching. It may be used by everyone for free.

The software on this website can be e.g. applied at universities, companies, or schools.


"Free graph theory software" has a graphical user interface (GUI) and works online without installation. Graphs are constructed by mouse, and a series of graph parameters and graph properties can be displayed (also during the construction).

Furthermore, the program allows to import a list of graphs, from which graphs can be chosen by entering their graph parameters or graph properties.

You can construct graphs with an editor using a mouse. Also, you can generate graphs as e.g. complete bipartite graphs, automatically.

Furthermore, the software allows you to load special famous graphs.

At the moment, undirected graphs without loops or multiple edges are supported.

Graph properties and parameters

A series of graph properties and parameters of your graphs can be displayed in a new window. With this feature, you can watch how the values change, during your construction. This can be quite useful for finding counter examples of conjectures.

→ Show supported graph properties and parameters


The software has a feature to visualise your graph automatically, which gives in most cases nice and beautiful graph embeddings into the plane. Of course, you can also make your own graph drawings with the mouse.

Importing graphs

You can import your own lists of graphs encoded in graph6 format and choose graphs from this list by their parameters. This can be usefull for graph enumeration or when testing a conjecture.

The program also includes special lists of (non-isomorphic) graphs, as connected graphs or cubical connected graphs, which you can import.

Once you choosed the graphs from your list, they are visualised and a list in graph6 format is shown, which you can copy/paste and save e.g. to some textfile.

As another feature, it is possible to reduce your list to the non-isomorphic graphs in your list.