How accurate is Google Translate? It depends heavily on the language. In the best published per-language tests, it kept the meaning of 92–94% of Spanish medical instructions, about 81–82% of Chinese, and only 55% of Armenian. Those studies date from 2019 and 2021, and the tool has improved since.
Below, we line up the real numbers from peer-reviewed research, language by language, and explain why a tool that handles Spanish so well once turned a painkiller into a weapon in Armenian. You will also see where machine translation is perfectly fine and where one wrong word costs too much. Explore our translation services for details.
Key Takeaways
- There is no single accuracy score for Google Translate: published results range from 94% for Spanish to 55% for Armenian in the same study.
- The most cited per-language figures come from two medical studies published in 2019 and 2021, so they describe older versions of the tool.
- A 2025 study of 26 languages found a 5% overall error rate and could not easily predict which languages would do well.
- Languages with huge amounts of online text paired with English tend to score higher than languages with little digital text.
- Machine translation suits low-stakes reading, while legal, medical and certified documents still need a qualified human translator.
How Accurate Is Google Translate, According to Published Studies?
Google does not publish an official accuracy score for each language, so the most useful numbers come from independent researchers. Two studies of hospital discharge instructions are quoted more than any others, because real bilingual reviewers checked the output sentence by sentence.
The 2019 JAMA Internal Medicine study
Researchers at the University of California, San Francisco ran 100 sets of emergency department discharge instructions, containing 647 sentences, through Google Translate. As reported in the study by Khoong and colleagues in JAMA Internal Medicine, 594 of the Spanish sentences (92%) and 522 of the Chinese sentences (81%) were translated accurately.
The team also asked how much damage the errors could do. About 2% of the Spanish sentences and 8% of the Chinese sentences had the potential to cause clinically significant harm. The most alarming example: “hold the kidney medicine,” which means stop taking it, came out in both languages as an instruction to keep taking it. Explore our AI and human translation accuracy for details.
The 2021 Journal of General Internal Medicine study
A second team, led by Dr. Breena Taira of UCLA, widened the test to seven languages. Twenty bilingual volunteers rated 400 translations of 20 common discharge phrases. According to the paper by Taira and colleagues in the Journal of General Internal Medicine, the overall meaning survived in 82.5% of cases (330 of 400), with a wide gap between the strongest and weakest languages.
The authors concluded that Google Translate “is inconsistent between languages and should not be relied on for patient instructions.”
Google Translate Accuracy, Language by Language
Here are the figures from both studies side by side. They are the best published per-language numbers available, but read the dates: the tests reflect Google Translate as it worked roughly between 2017 and 2020, on short medical instructions translated from English.
| Language (from English) | Khoong et al., 2019 | Taira et al., 2021 | What the researchers noted |
|---|---|---|---|
| Spanish | 92% | 94% | Strongest result in both studies; sentences written at a harder reading level caused more errors |
| Tagalog | Not tested | 90% | Second highest of the seven languages |
| Korean | Not tested | 82.5% | Matched the study average |
| Chinese | 81% | 81.7% | Medical terms and casual English phrasing raised the error rate |
| Vietnamese | Not tested | 77.5% | Nearly one in four phrases lost its meaning |
| Farsi | Not tested | 67.5% | The right-to-left direction of the script was not handled properly, which left some text unreadable |
| Armenian | Not tested | 55% | Lowest result; barely more than half the phrases kept their meaning |
Two things stand out. First, Spanish and Chinese landed in nearly the same place in both studies, which suggests the figures are not flukes. Second, the gap between first and last place is almost 40 percentage points inside a single app. Explore our accurate translation for official documents for details.
The Armenian result produced the study’s most quoted error. An instruction to take over-the-counter ibuprofen as needed for pain reportedly came back, when translated into Armenian, as advice to take an “anti-tank missile” for pain. It is funny for about one second, and then you picture the patient reading it.
Is Google Translate More Accurate in 2026?
Almost certainly yes for major languages, though nobody has published a fresh language-by-language table to prove exactly how much. The technology has changed several times since those studies were run.
- 2016: Google moved from phrase-by-phrase statistical translation to neural machine translation, which reads whole sentences at once.
- 2024: Google added 110 languages in what it called its largest expansion ever, using a large language model. Google’s announcement said the new languages represent more than 614 million speakers.
- December 2025: Google brought Gemini models into Translate to handle idioms and slang better, starting in the US and India with translation between English and nearly 20 languages.
Today the service covers roughly 250 languages and language varieties. More languages does not mean equal quality across all of them, though.
The most recent medical test backs up both the progress and the caution. A study published in The Journal of Emergency Medicine in 2025 checked discharge instructions in 26 languages and found an overall success rate of 95%. Five languages still scored below 90%: Amharic, French, Oromo, Portuguese and Yoruba. The authors wrote that the languages Google Translate handles better “are not easily identified.” French and Portuguese on the weaker list is a useful reminder that big languages are not automatically safe. Explore our technology’s role in modern translation for details.
Why Does Accuracy Vary So Much Between Languages?
Machine translation learns from examples, not from grammar lessons. The quality of the result follows the quantity and quality of what the system has seen.
Training data
Spanish and English share billions of words of translated text online: news, government pages, subtitles, manuals. Armenian, Oromo or Yoruba have a tiny fraction of that. Less material means more guessing.
Distance from English
Languages with different word order, writing systems or grammar give the system more ways to slip. Chinese has no verb tenses in the English sense, Korean puts the verb last, and Farsi runs right to left, a detail that tripped up the 2021 test.
Context and ambiguity
“Hold the medicine” can mean keep it in your hand, keep taking it or stop taking it. A human translator asks or reads the surrounding paragraph. A machine picks the statistically likely option, and sometimes the likely option is the opposite of what was meant. Explore our professional document translation services for details.
The type of text
Both major studies found that jargon, slang, typos and long sentences increased errors. Plain, short, well-punctuated sentences translate best in every language.
When Is Google Translate Good Enough, and When Is It Risky?
Used for the right job, Google Translate is a remarkable free tool. The question to ask is simple: what happens if one sentence is wrong?
| Usually fine | Risky without a human translator |
|---|---|
| Reading a menu, street sign or product label while traveling | Contracts, court filings, affidavits and other legal documents |
| Getting the gist of a foreign news article or email | Medical records, prescriptions, consent forms and discharge instructions |
| Casual chats with friends, hosts or online sellers | Birth, marriage and academic certificates for immigration or official use |
| Checking a word or phrase while learning a language | Marketing copy, websites and anything published under your name |
| A first rough look at a document to decide if it matters | Financial statements, patents and technical safety manuals |
Official paperwork has a second problem beyond accuracy. US immigration rules require that any foreign-language document come with a full English translation that the translator has certified as complete and accurate, along with a statement that the translator is competent in both languages. An app cannot sign that statement. We explain the details in our guide to USCIS certified translation.
What This Means When You Need a Document Translated
A 95% success rate sounds excellent until you apply it to a real document. A three-page contract can easily hold 100 sentences, so if that rate held, about five of them would be wrong, and you would not know which five. That is the practical gap between a tool that helps you understand and a translation you can submit. Explore our certified Spanish translation services for details.
For documents that will be read by a court, a hospital, a university or an immigration officer, a human translator who knows the subject reads for meaning, checks names and dates against the original, and takes responsibility for the result. If your paperwork needs a signed certificate of accuracy, our certified translation services are handled by human translators from start to finish. For more on that difference, see our post on the benefits of human translation.
Frequently Asked Questions
What is the accuracy rate of Google Translate?
There is no single figure. In peer-reviewed tests on medical instructions translated from English, Google Translate kept the meaning 92–94% of the time in Spanish, about 81–82% in Chinese, 77.5% in Vietnamese, 67.5% in Farsi and 55% in Armenian. Those results were published in 2019 and 2021. A 2025 study across 26 languages reported 95% overall, with several languages still below 90%.
Which language is Google Translate most accurate for?
Spanish has the strongest published record, scoring 92% in a 2019 JAMA Internal Medicine study and 94% in a 2021 Journal of General Internal Medicine study. As a rule, languages with large amounts of text already translated to and from English perform well. Still, a 2025 study found French and Portuguese under 90% on medical instructions, so a widely spoken language is not a promise of accuracy.
Can I use Google Translate for USCIS or other official documents?
No. Federal regulations require every foreign-language document submitted to USCIS to include a full English translation that the translator has certified as complete and accurate, plus a statement that the translator is competent in both languages. Software cannot provide that signed certification. Courts, universities and many state agencies ask for something similar, so official documents should go to a qualified human translator. Explore our human Arabic translation services for details.
Is Google Translate accurate enough for medical or legal use?
Researchers say not on its own. The 2019 study found that 2% of Spanish and 8% of Chinese sentences in discharge instructions could cause clinically significant harm, and the 2021 authors concluded the tool should not be relied on for patient instructions. Legal texts carry similar risks, because one reversed meaning can change an obligation. Use a professional translator or interpreter for both.
Has Google Translate improved in recent years?
Yes. Google switched to neural machine translation in 2016, added 110 languages in 2024 using a large language model, and began rolling out Gemini-based translation in December 2025 to handle idioms and slang more naturally. Quality for major languages is clearly better than a decade ago. Independent, language-by-language measurements are published slowly, though, so current numbers for most languages remain unknown.
Need a Translation You Can Rely On?
Google Translate is great for getting the gist. When the document matters, let a human translator handle it. Chat with our team for a free quote, or call 1-800-230-7918 and tell us what you need translated.
