BioCompare is a web service that aims to visualize and compare biological networks starting from microarray experiments. The system automatically computes the Pearson correlation matrices for each uploaded microarray data. All resulting matrices will be filtered applying a default threshold of 0.9 required to visualize only edges that are strongly correlated. BioCompare provides also the possibility to compare two different networks. This feature is essential for biologists and bioinformaticians for the analysis of time series microarray data or experiments performed on different biological tissues. Please consider to browse the BioCompare Encyclopedia to discover all system features in details.