Reference Gerber Viewer v. 2.8 free, cloud-based online web service displays all meta-information contained in Gerber X2 files: layer structure, where via pads are, CAD netlist, component reference descriptor and pin number of all pads.
Displays extra information contained in X2 file. Provides verification of Gerber output software. Checks generated Gerber and NC files. Provides validation of input and arbitrates discussions about interpretation of a file. No software to download, install and maintain.
Ucamco
gerber-viewer.ucamco.com