Have smartphone, will travel: How far can you get with just passport, wallet and phone?

Pretty far, it turns out – or as far as your battery and data will last

Sure, you know your mobile phone is essential, but exactly how much can you rely on it?

A few days ago in Japan, Google threw down a gauntlet: how far can you get in a foreign country, where you can’t be sure of finding an English speaker, where the words, even the alphabet, are unfamiliar, and where the address system is notoriously tricky?

So there I was, in Tokyo, charged with solving a series of puzzles using a smartphone and nothing more.

First, I had to get myself from bustling Tokyo (where English speakers are plentiful and, because they are Japanese, endlessly helpful) to the distant city of Kanazawa.

I had a JR train pass, which is the best way to get around Japan for a foreigner and which offers fantastic value, though you must buy it before you arrive in the country. So first, I needed to get to Tokyo station.

This being a Google challenge, I’d been briefed on exactly which of the company’s apps would be helpful. First up was Google Maps which includes public transport in its knowledge base. I was using the company’s new handset, the Pixel XL. Speaking the name of the station was enough for it to guide me on foot to the nearest underground station, with detailed instructions of which train line and platform I needed.

To be frank, for visitors to Japan, this is an essential app. It gives you accurate details of how long your journey will take, even down to the time changing trains. It is reliable and comprehensive enough to make the most uncertain traveller feel completely confident. I used Google Maps plenty on this trip and it never let me down.

Since the numbering of houses in Japanese streets is not predictable, being based on in which they were built, this app was unbelievably valuable later, when searching for a street address.

Another app, Citymapper, also proved useful. Citymapper only works in selected cities, but has phenomenal detail levels, even telling you which part of the train to board so you can exit most quickly.

Once at Tokyo station, I relied on the fact that the station staff spoke good English, gave me my ticket and directed me to the platform. I’m not sure any phone app could have been as helpful.

On board, the two-hour-and-a-bit journey to Kanazawa was uneventful, with Google Maps as well as the carriage announcements letting me know how much further to go.

I’d note in passing that Japan Rail trains are super-cool, from the conductors who touchingly bow as they enter and leave each carriage, to the seats which all face in the same direction but which, with one press of a lever can be spun through 180 degrees so groups of four or six face each other.

Kanazawa is a city surrounded by mountains. It has two national parks, two rivers running through it and is picturesque. It’s known for gold leaf, which it has been producing for hundreds of years and almost all the gold leaf in Japan is made here.

At the Kanazawa Noh Museum, my first task was to find masks that matched items in my smartphone photo library via cryptic clues sent by the Google messaging app Allo. Allo is a useful messaging app which, like many Google apps, works as happily on Android and iOS devices.

On the Pixel phone, Google Photos is where pictures are found. It can search in sophisticated ways. So, in response to a clue for “something that was a colour and a fruit”, typing orange into the search box revealed photos dominated by the colour. This also works if you type, dogs, say, and canine photos pop up. It’s all done by machine learning: you don’t need to categorise photos. It works spookily well. Apple has recently revealed a similarly impressive feature in its latest iPhone software.

The next app to be demonstrated, Duo, is for video calling. It’s Google’s answer to Apple’s FaceTime. It promises smooth switching from wi-fi to 4G and its headline-grabbing USP is Knock Knock, which shows live video of an incoming call before you decide to answer, on the basis that if what the caller is doing is intriguing enough, you’re more likely to answer.

Apple’s FaceTime has an audio option, which is handy if you’re in a poor cell-tower area, but Duo lacks this. Still, I found video calls – especially when in a wi-fi area when they were free – to be as effective here as the first time I used Apple’s version. Since the challenge involved a game of charades with, I kid you not, a distant geisha acting out Japanese proverbs, Duo was essential. Not everyone finds themselves playing video charades to overcome the language barrier, but I guess you never know.

The camera on the Pixel XL, is excellent. Recently it has been found to be prone to lens flare, which will be compensated for by software in a future update. Features such as creating quick animations were easily mastered and I like the way the burst shots have a kind of motion when you swipe past them in the phone’s photo library.

Two other apps were real stand-outs on the Japanese journey.

Google Translate, obviously, was a real help. There are other translation apps around but this is arguably the most versatile. You can type a question in English, or speak it, and the phone will display your question in Japanese, speak it for you and show a phonetic transliteration of what you should say in Japanese if you’re brave enough.

I found that sometimes it was enough to hold the phone up and let the native speaker hear what the phone said, though asking them to read the text worked better.

You can also touch a camera icon and the app can translate printed text. This was brilliant, though most effective when you worked through translation a bit at a time: translating a whole page swapped you to a new page and it was hard to get back again, so a new photo was required.

There’s a conversation mode which kept things going well, though using this feature took a bit of practice. Offline capabilities meant you didn’t need a constant data connection, though not every feature worked without it. But this is undoubtedly a highly accomplished app, especially on Android.

A word on phone data, on which nearly all these apps depend. Data in Japan is prohibitively expensive, so it’s worth considering a local data sim, and running a separate handset for it. I used a prepaid sim card from Bmobile which cost £22 for 5GB of data spread over 21 days. It was a data only sim; I used my regular phone for calls.

Finally, there’s Google Assistant. In its most advanced state, this is only available on the Pixel and Pixel XL phones right now. And as voice-activated assistants go, it’s excellent. Like Apple’s Siri, it’s clever enough to handle follow-up questions. You can say “What’s the weather like in Tokyo?” wherever you are and follow up with “How about tomorrow?” and it’ll know you’re still talking about Tokyo.

I notice, mind you, that neither can manage the answer to the question, “Was Ronnie Barker older than Ronnie Corbett?”. The underrated Evi app (now owned by Amazon but still available for Android and iPhone) passed this test happily, though better using text input than voice. Since you ask, Barker was born first but Corbett lived longer.

International travellers also need to be mindful of battery life. The full-on, all-day challenges sapped the battery on both my phones (Pixel and iPhone). If you’re relying on your phone in this way, remember to pack a rechargeable battery. True, I was posting on Instagram, Facebook and Twitter at a fair old rate, but even a less busy day could see the battery failing before nightfall.

So how good was Google at getting me through the challenges? Pretty marvellous, actually. Finding an address in a place like Japan is horribly confusing and unnerving. Google Maps sorted this perfectly, whether I was searching by landmark, street address or even co-ordinates, though this will be a function most will avoid. Being able to translate written text as well as spoken words was also a lifeline.

To be honest, just as effective and ultimately more pleasing were the interactions with locals, you know, real human beings.

Even in Kanazawa, many spoke enough English for me to muddle through – and their English was 300 times better than my Japanese.

One taxi driver, ferrying me across town, took such pride in pointing out the museum, the town hall, the castle, the stunningly beautiful zen-like gardens that it was deeply touching.

It was moments like these which were the real highlights of the trip. Though I was glad to have my Pixel phone in my pocket as back-up.