The iPhone maker, which has been slow to embrace artificial intelligence, will weave it into the technology that runs on billions of devices.

Nearly two years after OpenAI ignited a race to add generative artificial intelligence into products, Apple jumped into the competition on Monday, as it revealed plans to bring the technology to more than a billion iPhone users around the world.

During a two-hour presentation from its futuristic Silicon Valley campus, Apple said that it would be using generative A.I. to power what it is calling Apple Intelligence. The system will prioritize messages and notifications and will offer writing tools that are capable of proofreading and suggesting what users have written in emails, notes or text. It also will result in a major upgrade for Siri, Apple’s virtual assistant.

Apple’s plans to offer A.I. in its iPhones represents the next step in bringing artificial intelligence into the consumer mainstream. Apple, the marquee name of Silicon Valley, could do more than any other company to add credibility to a technology that has more than a few critics, who worry that it is mistake-prone and could add to the flood of misinformation already on the internet.

Apple’s new A.I. features could also help calm concerns that the iPhone maker had slipped behind its biggest rivals in the tech industry’s embrace of artificial intelligence. The value of other tech companies, like Microsoft and Nvidia, has ballooned because of their aggressive A.I. plans. Earlier this year, Microsoft dethroned Apple as the most valuable technology company in the world.

While introducing its new A.I., Apple emphasized how it planned to integrate the technology into its products with privacy in mind. The company said that the technology, which can answer questions, create images and write software code, would perform sensitive tasks. It showed how the system would be able to automatically determine if a rescheduled meeting time would complicate plans to attend a child’s theater performance.

It said that the computer processing would be done on an iPhone rather than in data centers, where personal information has a greater risk of being compromised. For complex requests that require more computing power, it has created a cloud network with Apple semiconductors that, it said, is more private because it’s not stored or accessible, even by Apple.

Apple struck a deal with OpenAI, the maker of ChatGPT, to support some of its A.I. capabilities. Requests that its system can’t field will be directed to ChatGPT. For example, a user could say that they have salmon, lemon and tomatoes and want help planning dinner with those ingredients. Users would have to choose to direct those requests to ChatGPT, ensuring that they know that the chatbot — not Apple — is responsible if the answers are unsatisfying. Sam Altman, the chief executive of OpenAI, attended the Apple event.

Apple’s deal with OpenAI, which already has a close partnership with Microsoft, is another indication that the young San Francisco company has clearly become the tech industry’s leading developer of A.I. technology

“As we look to build in these incredible new capabilities, we want to be sure that the outcome reflects the principles at the core of our products,” said Tim Cook, the chief executive of Apple. “It has to be powerful enough to help the things that matter the most to you. It has to be intuitive and easy to do.”

Apple also said that it would be making improvements to its iPhone software system. This fall, messaging will add the ability to schedule messages and respond to messages by tapping back with more emojis. Apple will also release a redesigned Photos app to make it easier to browse images by topics like pets and travel. And it said that iPhone users would be able to send high-resolution images to Android smartphones.

Apple brings several strengths to the A.I. race. Its semiconductor development team is among the most talented in the industry and has been making chips that power complex A.I. functions for years. The company has also marketed itself as being better at protecting people’s personal information than its rivals because it makes money by selling devices, not by advertising.

But Apple has several weaknesses that could slow its A.I. development. The secretive company has struggled to recruit and retain leading A.I. researchers because it limits how much research it publishes. It has also sought to license published material and objected to collecting it without permission, as other generative A.I. companies have done to build and train their technology.

Sam Altman, wearing a blue shirt, sits in a large crowd.
Sam Altman, the chief executive of OpenAI, attends the annual Apple developer conference event.Credit...Carlos Barria/Reuters

Though Siri has been around for more than a decade, Apple has let the voice assistant languish. The assistant has frustrated users with its failure to recognize various requests, and its ability to actually converse is limited because it is programmed to follow each individual command.

Generative A.I. could improve Siri because it has been trained on spoken conversations pulled from podcasts and videos. The result is a system that can mimic the way people talk.

Apple said that Siri would be able to remember the context of something that a user has raised with it. For example, if someone asks for the weather in Muir Woods National Monument and later asks to schedule a hike there, Siri will now know that the hike it is scheduling is in Muir Woods.

Siri will also understand more of the things that people want to get done in iPhone apps. For instance, users can ask it to show a photo of a friend and it will find and surface those images for people in the Photos app. It also will be able to perform tasks for people like finding an image of a user’s driver’s license and filling it out into a form.

Other generative A.I. capabilities that Apple demonstrated included automatically summarizing audio recordings, allowing customers to create movies from photos by writing a description, and cleaning up photos by removing distracting images in the background.

“This is the biggest event for investors since the iPhone because they have to infuse A.I. into their products to thrive,” said Gene Munster, a managing partner at Deepwater Asset Management, which invests in emerging technology companies. “Today was about showing that they will make A.I. a core competency and that they can deliver an A.I. experience that consumers want.”

The event was an important milestone in Apple’s relationship with developers, as well. Tensions have flared between the company and app makers over the past year, as Apple has resisted new rules in Europe designed to loosen its grip on the App Store. The rules require Apple to allow third-party payment alternatives that could circumvent the 30 percent fee it collects on app sales. But developers say that Apple has responded by introducing alternatives that would make such a change prohibitively expensive.

Apple is facing similar challenges in the United States. A federal judge in San Jose, Calif., is weighing whether the company can proceed with a plan to collect 27 percent of sales on alternative payment systems. And the Justice Department also sued Apple for rules that prevent other companies from offering cloud-streaming game apps, digital wallets and other alternatives on iPhones.

Against that backdrop, Apple sought to emphasize the benefits it offers developers. During the event, it showed how its Apple Intelligence tools would be available to make apps more useful to customers.

Apple said that later this month it would be expanding sales of the Vision Pro, its mixed reality headset, beyond the United States to China, Japan and Europe. The company also unveiled new capabilities for the headset, including the ability to view older photographs in three dimensions and to create a giant, virtual display for a Mac.