The best translation tool while traveling? Your photo app.

At a supermarket in northern Spain, I blinked at the screen in the self-checkout lane, unsure of what the machine was asking me to do. Then, in a snap, I understood.

“Skip,” I read on my phone’s photo translation app while pressing the “Saltar” button on the automated register, bypassing the customer loyalty card step to pay for my groceries - all without even a whimper for help.

The secret to reading a foreign language is at your fingertips - index, thumb or whichever digit you use to take a photo. With a phone’s photo app or the Google Translate app, international travelers can decode the local language by simply training the camera lens on the foreign text and translating the words and phrases into their mother tongue. The tools, around for years, have grown more sophisticated and expansive.

“Photo translation apps can be excellent support tools for people traveling for leisure or business to help with simple tasks like translating menus, signs or labels,” said Kirsten Campbell-Howes, a language learning expert and director of learning design and science at Preply, an online language tutoring service. “They can help on the spot when a human isn’t available to translate or assist.”

We’ve come a long way from old-timey bilingual print dictionaries and even more modern online translation services. Typing blocks of text, sometimes with accents or umlauts, into your phone can be painstakingly slow and tedious, if not altogether fruitless. On several occasions, I have abandoned the task, choosing instead to muddle through without fully comprehending the situation or asking an English-speaking stranger for help.

On my most recent trip to Europe, however, I switched to photo translators. Wherever I looked, the English language materialized before my eyes - in subway stations and grocery stores, on street signs and soup cans, adorning T-shirts and tote bags. I felt as if I had broken through the fourth wall of Duolingo.

The system isn’t perfect - I did encounter misspellings and translation errors - but it was efficient and accurate enough to help me with basic tasks and activities in Spain, and navigate a foreign country with more confidence and independence.

“It’s good enough to understand and make yourself understood when traveling,” said Jeff Opdyke, a Portugal-based contributing editor with International Living. “One hundred percent a travel necessity.”

If the backdrop was distracting, I could tap the text and read the passage in a simpler format: vertically, with the local language stacked atop the translated section.

To use Google Translate, I clicked the “Camera” icon on the bottom right and positioned the camera over the text. The app then overlayed the translation onto the original script. (To pull the curtain back, Google explained that Google Lens reads the text from your camera viewfinder or uploaded photo, sends it to Google Translate and then pastes the translation over the original phrase.)

If my camera jiggled, the text would sometimes untranslate. So to immobilize the words, I pressed the shutter button with a little X and a big A. In addition, by clicking “Send to Translate Home,” I could read a streamlined version of the original and translated texts.

Because I was in Spain, where signs often appear in Spanish and Catalan, I set the language to “Detect Language” before snapping away. But you can choose any language, from Abkhaz to Zulu.

Once in Spain, I went on a translating spree. I translated informational signs in Madrid subway stations, best behavior guides on trains, restaurant menus, food labels at grocery stores (a lifesaver for people with dietary restrictions), frosted decorated cookies at a bakery, whimsical T-shirts and magnets in boutiques, a woman’s fan in a subway car, graffiti scrawled on buildings and the settings on the hotel’s fitness center equipment.

Even though Madrid’s Prado museum offered plaques in multiple languages, the tool came in handy at the art museum in Oviedo, where text was Spanish only. At my hotel in the same northern town, I photo-translated a note on a bottle of water before I drank it, in case it was not gratis.

“Drink me, I’m free,” it read. So, I did.

With my phone’s photo app, I couldn’t always line up the text and activate the “Live Text” icon. This was especially difficult when I was moving, such as on the subway. Google Translate worked better in high-velocity situations.

To my advantage, I was translating simple phrases in a common language.

“Languages like English and Spanish generally translate well, but not all languages are translated effectively,” Campbell-Howes said. “Chinese, for example, which is highly context dependent, can often be translated very poorly by these apps.”

In Madrid, I noticed an intriguing handwritten sign for a tailor and artist that may have included Greek words. One of the apps took creative liberties with its translation, including one word that resembled an English curse word.

Opdyke recommended downloading your languages in advance - go to the list of languages and click on any with the download symbol, a circle with an arrow - so you can use the apps offline. I neglected to do this on my first outing to a grocery store in Madrid. Deep in the soup aisle, I lost service. So I had to stand by the store’s open door to read the cans, smiling sheepishly at confused customers.

Finally, some businesses, such as merchants, museums and banks, may not allow photos and may mistake your translation tool for photography. In these cases, you may have to revert to the vintage approach to translation and ask for help.

“For somebody who is passing through a foreign land, it’s a godsend and a tremendous amount of fun,” said Alexander Arguelles, a linguist, educator and founder of the Alexander Arguelles Academy of Languages and Literature.

But, Arguelles said, you won’t become fluent using these apps. For that, he added, you need to learn the language by speaking and reading through your own personal lens, not the phone’s.