European officials said the coming rules are forcing American tech giants to take a step back.

“There has not been any pushback from American companies,” said Věra Jourová, the European Commissioner for Justice, Consumers and Gender Equality. “If anything, they seem very eager to understand how exactly they can comply with the regulation.”

Officials from Facebook, Google and other companies said in interviews that they had been working to give people more control over what data they share anyway. In the past, many of the companies fought back in European courts over privacy rules and declined to offer certain products in the region rather than redesign them to meet privacy standards.

The coming of the new rules has nonetheless pushed a huge scale of internal change, Gilad Golan, Google’s director for security and data protection, said at a San Francisco event last month to introduce new security features. “When G.D.P.R. goes into effect in 2018, we will be ready,” he said.

The biggest challenge, he said, has been preparing for the regulation’s mandate that people in Europe must have control over how their digital data is organized. Google, he said, has had to go through each of its services — from Gmail to its Cloud storage services — to comply. Since the new rules require individuals to give their consent before a company accesses data, for example, Google has had to redesign many consent agreements, as well as change underlying technology to make it easier to remove someone’s data.

“For a company with infrastructure of our size, it takes a lot of work,” Mr. Golan said.

Facebook has also taken multiple steps to deal with the coming rules. On Sunday, the company began offering a new privacy center that puts user security settings on one page instead of dispersing them across different sections of the social network. While the company said the changes was separate from its preparations for the new European regulations, Facebook’s chief operating officer, Sheryl Sandberg, connected the two in a speech in Brussels last week.

The new privacy center would give Facebook a “very good foundation to meet all the requirements of the G.D.P.R. and to spur us on to continue investing in products and in educational tools to protect privacy,” Ms. Sandberg said.