Online fraud's increased by nearly 50% in the past year according to statistics in the Chief Constable's annual report.
Gary Roberts said cybercrime reports crept up steadily during the pandemic when we all got online to keep in touch and do our jobs.
As internet activity increased, criminals became more and more sophisticated.
Mr Roberts said getting your money back if you've been a victim is unlikely and the best prevention is to tighten up on your online security.
He added that we all need to be as good as protecting our online life as we are at securing our homes and cars.