Freerouting — PCB Autorouter

An autorouter that takes a DSN file from your PCB tool, routes the connections and returns an SES file to import back. It supports 90-degree, 45-degree and free-angle routing, and an optimisation pass that improves existing tracks rather than routing from scratch. This is precisely the piece missing from KiCad — its built-in autorouter was removed years ago, and this is what the community has used since. Written in Java, so it runs on every operating system. On dense boards it is worth remembering that an autorouter is a starting point, not a substitute for judgement.