There are a few third party indexes used by SEOs for this purpose: http://www.opensiteexplorer.org/ http://www.opensiteexplorer.org/ https://www.majesticseo.co

There are a few third party indexes used by SEOs for this purpose: http://www.opensiteexplorer.org/ http://www.opensiteexplorer.org/ https://www.majesticseo.com/ https://www.majesticseo.com/ https://ahrefs.com/ https://ahrefs.com/ Even once you own the domain, the links Google reports in GWT can be rather hit and miss...