Google has unveiled a mobile phone application that allows users to translate chats instantaneously.

Google Translate can use devices running its Android operating system to allow translation of English to Spanish and vice versa.

Users will have to punch a key to activate the translation between sentences, but Google expects the service to operate in real-time within 18 months.

It uses technology similar to the updated Googles application, which uses a phone’s camera to snap images of sudoku puzzles and, via internet, whiz back the solution in seconds, the Daily Mail reports.

Google Translate works by recording the user’s speech, sending the recorded words to the company’s vast servers, which then send back an audio translation.

The ‘Alpha’ trial version works only in Spanish and English but Google expects to add new languages soon.

In December, an iPhone application called WordLens became an internet sensation after a video demonstrated how it uses the iPhone’s inbuilt camera to recognise text that is viewed through the lens. It too only worked with Spanish and English.

Google already has an online text translator and while early versions of it sometimes produced little more than gobbledegook, its ever-growing database of words has now enabled it to achieve far greater accuracy.

It now covers more than 52 of the world’s estimated 6,000 languages.

As with automatic text translation, Google hopes the technique will become more sophisticated with the help of millions of users around the world.

But Google Translate is a giant leap forward in technology, eschewing text translations for direct speech, and it defies expert opinion.