The Press Council will offer membership to blogs and digital media and will get tougher powers for dealing with complaints.
The move follows a review by the council's main funder, the Newspaper Publishers' Association, after considering recommendations by the Press Council and a Law Commission Report.
Association editorial director Rick Neville said most publishers felt the time had come to strengthen the council's authority and extend its coverage to handle complaints against digital media, including blogs.
"The media world is changing and fragmenting. It's important that a body set up to maintain high standards, and provide an avenue for reader complaints, keeps pace with those changes," he said.
Press Council chairman, former High Court judge Sir John Hansen, said he welcomed broadening the council's remit.
"It's important that all consumers of media have an avenue for complaint, and for them to believe their complaint has been handled with fairness and professionalism."
Digital media will be offered a new form of membership with a fee based on the size of the entity and its commercial or non-commercial status. They must agree to the same statement of principals and complaints process as other members.
Under the changes the council would also have the right, in exceptional circumstances, to censure a magazine, newspaper or website by unanimous decision of the council.
Other new measures include greater power over where an adjudication appears in a publication.
Members will be required to regularly publicise information about the Press Council's complaints process, and member websites will be required to provide an easy-to-find complaints channel with details on making a complaint.
The council will also have the power to direct that elements of a story be removed from an online article, or for a story to be taken down.
The new structure will take effect from May 1.
The Press Council was established in 1972 to adjudicate on complaints against newspapers. It was extended to include magazines in 1988, and member's websites in 2002.