What Is Back Translation and Why Is It Important?

Back translation, or re-translating a document from one language back to its original language, can be a useful way to gain insight into your final translated product.


“Can you read this and let me know what you think?”

Asking a bilingual employee for a quality review may seem like an easy way to ensure the quality of your translations. But in reality, it’s like asking your car-enthusiast uncle to help repair your car instead of taking it to an auto shop. Sometimes it can work, but more often than not, it ends in disaster. (And you still have to take the car to the mechanic anyway.)

Quality assurance is one of the most important parts of any translation process. One way to evaluate quality, especially when there are multiple translation options, is to review back translations.

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What is back translation?

Back translation, also called reverse translation, is the process of re-translating content from the target language back to its source language in literal terms. For example, if you’re translating content from English to Swedish, the translator would also write a back translation English so the intention of the translated option is easily understood. Back translations don’t impact the translation memory or other resources like glossaries used by the translator.

Back translation (sometimes referred to as double translation) is most helpful when the content at hand includes taglines, slogans, titles, product names, clever phrases and puns because the implied meaning of the content in one language doesn’t necessarily work for another language or region. The back translation offers the content owner the opportunity to review what creative liberties the translators took to adapt the content for their market. And oftentimes, for content that is this complex, the translator will offer multiple options so the source content owner can make a decision that makes the most sense for the brand.

This is often confused with double translation, which is a method of translation where one translator creates multiple versions of a piece of content to account for the nuances in different words and phrases.

Back translation is often used as a quality assurance method. The back translation process looks like this:

  1. A linguist translates the original source text into the new language.
  2. Then the linguist translates the localized string back into the source language literally to convey the meaning of the translation
  3. The content owner or project manager selects the option that best represent the brand, tone and intention of the source content

Why would you use the back translation method?

Often, translation consumers think that they can measure quality between translators or agencies by doing a “blind test.”

They send a project to one vendor for translation. Then, they send the completed translation to a separate vendor, asking them to translate it back to the original language. Lastly, they compare the two versions to see how similar they are. Their assumption is that they can spot errors by comparing the versions.

Is this process doomed to fail?

Errors can be introduced at any point in the process. It’s highly unlikely that you’ll ever find an exact copy from back translation because of the differences between the source text and the translated text version that happen during the standard localization process.

To make content persuasive, effective, and relevant to your audience, translators often introduce subtle cultural changes (called transcreation).

Here’s an example of what that looks like:

French TranslationBack Translation
Des mots qui changent le mondeWords that change the world
Des mots pour un monde meilleurWords for a better world
Quand les mots font avancer le mondeWhen words help the world move forward
Des mots pour faire avancer le mondeWords to help the world move forward
Les mots au cœur de nos viesWords at the heart of our lives
Des mots, des viesWords, lives

You can see that there’s a variety of different ways to say the same slogan, “Move the World with Words.” That’s OK for the goals of this project: a marketing slogan should resonate with the intended audience and be catchy and short enough to fit at the top of a flyer or Facebook ad, and in this case, convey the right metaphor.

The real usefulness in back translation comes as a method of quality assurance. Marketing slogans, blog posts, and sales collateral may not need perfect accuracy, but other types of content will. Using back translation puts you in the driver’s seat as a way to manage risk.

The best types of back translated content

When a blog post has been translated, the content is still expressing the original source, and there shouldn't be a need for back translation because the language should not have strayed too far from your original message.

Often translators are simply changing idioms, analogies, and references that better relate to the culture they're writing for.

This could also include restructuring sentences or maybe even paragraphs and sometimes swapping content like images—but the original idea and even wording, for the most part, will remain.

However, other types of content might require back translations. Industries with important, high risk content that requires perfection — for example, in the medical field, where mistranslations could mean the difference between life and death.

For certain industries, regulatory requirements, ethics committees, and institutional review boards mean back translations must be a part of any translation process.

That includes content like:

  • Medical: Clinical research, medical devices, clinical trials, pharmaceutical companies, and consent forms
  • Data: Survey results, questionnaires, polling, and research
  • Legal: Contracts, legal documents and instruments, case files and other important paperwork, insurance policies, and other binding documents
  • Finance: Financial reporting, earnings, performance, and regulatory filings
  • Manufacturing or Product: Operating instructions, safety manuals, software agreements and copy, food packaging, import/export paperwork

When to use back translation services...and when to not to

Back translation can be a useful tool in your localization strategy, but it’s not necessary for every single company’s needs (or even every single project). If you’re working with a trusted localization partner like Smartling, rigorous QA checks and automated reporting can give you peace of mind for most of your translation needs.

There are a few key use cases where back translation makes sense.

Use back translation if…

  • You work in a highly regulated industry like financial services, healthcare, or insurance and need to consistently manage risk or meet regulatory requirements
  • You’re more concerned with accuracy and specific terminology than creativity, style, or expression
  • You have more time and budget, since back translation adds a layer in the process and takes time for different languages

The source content is highly creative or emotionally charged

You don’t need back translation if…

  • Your work isn’t highly sensitive or carries risk
  • You care about the creative expression, style, and grammar more than a “perfect” translation
  • Your content deals with ambiguous topics or big ideas and requires a more nuanced touch with localization

Back translation is just one way to ensure translation quality assurance. With Smartling’s transcreation tool, you can seamlessly work back-and-forth with translators so you can understand exactly how the process works, add back translations to your process, select your favorite transcreation options, and more.