  Many networks exhibit some community structure. There exists a wide variety
of approaches to detect communities in networks, each offering different
interpretations and associated algorithms. For large networks, there is the
additional requirement of speed. In this context, the so-called label
propagation algorithm (LPA) was proposed, which runs in near-linear time. In
partitions uncovered by LPA, each node is ensured to have most links to its
assigned community. We here propose a fast variant of LPA (FLPA) that is based
on processing a queue of nodes whose neighbourhood recently changed. We test
FLPA exhaustively on benchmark networks and empirical networks, finding that it
can run up to 700 times faster than LPA. In partitions found by FLPA, we prove
that each node is again guaranteed to have most links to its assigned
community. Our results show that FLPA is generally preferable to LPA.
