Google on Wednesday launched its latest attempt to catch up with Facebook in mobile messaging, targeting a market that is quickly expanding to become one of the most important platforms on mobile devices.

The search company has drawn on its substantial investment in artificial intelligence technology to try to set the new service, called Allo, apart.

First announced in May and released in an English-only version on Wednesday, Allo uses AI to suggest automated responses for users to send. It also acts as the first outlet for Google’s new intelligent digital assistant, which is designed to handle searches or help users complete tasks without sending them to a separate search box.

The launch follows a long history of messaging initiatives at Google. With names such as Google Talk, Google Chat and Hangouts, they have failed to match Facebook, whose Messenger and WhatsApp services each claim more than 1bn users.

“The very fact that [Google] have had numerous efforts in the messaging space and they continue to persevere shows how important messaging is as a platform in its own right,’ said Geoff Blaber, an analyst at CCS Insight. Facebook has been racing to turn Messenger into a platform for games and commerce, this year opening it to “bots”, or text-driven apps, made by other companies.

Nick Fox, head of Google’s consumer communications group, said the company believed messaging services were on the brink of significant changes caused by the rise of AI, opening the market to new entrants such as Allo despite the large audiences some companies have already amassed.

“You can say messaging is a solved problem, but we don’t see it that way,” he said. “We see it as a paradigm shift in messaging.”

Google’s approach to privacy on Allo immediately drew criticism from Edward Snowden, the former US government security contractor who exposed widespread internet surveillance. Over Twitter, Mr Snowden drew attention to the fact that messages will be stored indefinitely, rather than deleted after a period of time, as Google had at first indicated.

The data policy highlights the perennial tension inside Google between on the one hand giving users more privacy, and on the other collecting and keeping large amounts of personal data so it can personalise its services and advertising.

“What is #Allo? A Google app that records every message you ever send and makes it available to police upon request,” Mr Snowden wrote.

In another tweet, he added: “Free for download today: Google Mail, Google Maps, and Google Surveillance. That’s #Allo. Don’t use Allo.”

Google said the app had been designed to give users “transparency and control”, and that they would be able to delete their entire chat history manually whenever they wanted.

Allo employs AI to analyse the last message received and suggest automated responses users might want to send, listing options that are dispatched with a single tap. Using its image-recognition technology, Google also analyses photos received over the system and offers responses. A picture of a friend’s pet, for instance, might prompt a suggested response of “Cute dog!”

Despite the potential this opens for an AI-assisted exchange in which humans merely swap messages suggested by computers, Mr Fox said: “We’re not trying to replace human expression.” The feature is designed to be more like a spellcheck function to speed and improve the quality of the communication, he added.

The intelligent assistant is also designed to offer help during a chat, for instance offering to search for nearby restaurants if it senses humans are discussing food. This is the first time Google has offered a search function that two people can use at the same time, said Mr Fox.

Unlike Facebook’s messenger, Allo has not yet been opened to other companies’ bots. However, Google showed off potential examples of third-party services working in Allo in a demonstration in May, and Mr Fox hinted that it may expand the service to other developers before the end of the year.

Despite the attempts to use AI to enhance mobile messaging, analysts have predicted that it would be hard for Google to break into a market where most mobile users are already tied into a range of services to talk to friends and family. “First and foremost, people use messaging to communicate with each other. Google need to get the network effects first,” said Mr Blaber.

Allo includes an option for messages to be sent using end-to-end encryption. The technology puts communications beyond the reach of hackers and makes it impossible for law enforcement agencies to see what has been said, something that has drawn complaints from governments on both sides of the Atlantic when used by other companies. Facebook’s Messenger also offers end-to-end encryption as an option, while it is the default setting in WhatsApp and Apple’s iMessage service.