The most accurate Spanish translator

What the studies found for Spanish

Google Translate and ChatGPT both have strong results in the Spanish studies listed here. But those results don't establish a single winner for everything you might translate, from a school assignment to a business website. The evidence here is about medical text.

That distinction matters.

In Khoong et al., published in JAMA Internal Medicine in 2019, Google Translate got 92% of Spanish emergency department discharge sentences right. Still, 2% could have caused harm. Taira et al., 2021, found that Google Translate kept the meaning in 94% of Spanish emergency department statements.

The direct comparisons with ChatGPT don't give you a clean winner:

• Kong et al., BMJ Quality & Safety 2025, found Spanish sentence accuracy of 97% for ChatGPT-4 and 96% for Google Translate. The authors found no significant difference and advised against relying on machine translation for high-stakes medical instructions.
• Brewster et al., Pediatrics 2024, found clinically significant errors in 3.3% of Spanish translations from ChatGPT, 6.7% from Google Translate and 5% from professional translators. There was no significant difference between them.
• Ray et al., JAMA Pediatrics 2025, gave GPT-4o a score of 98.3, compared with 96.7 for professional human translators, using the MQM quality framework for Spanish patient instructions.

That last result is a quality score, not a percentage of sentences translated correctly. Keep the measures separate when you compare the studies.

Google Translate for Spanish

Google Translate has Spanish medical results across several studies here, including both emergency department discharge sentences and statements. If you want published evidence rather than a company's own comparison, there's evidence to look at.

Is it the most accurate Spanish translator? Not from these results alone. Its accuracy was close to ChatGPT-4 in the Kong study, and the authors didn't find the difference significant.

For your work or school text, these studies don't provide a measured accuracy rate. You can weigh the medical findings, but don't turn them into a promise about a different kind of document.

ChatGPT and GPT-4o for Spanish

ChatGPT deserves a place in the comparison, with a distinction between the versions studied. The results above refer to ChatGPT, ChatGPT-4 and GPT-4o, not a single model tested across all those studies.

GPT-4o's score in the Ray study is worth noting, but it doesn't establish that it's more accurate than professional translators on every Spanish task, or that it would win the same comparison on your text.

And the lower error rate for ChatGPT in the Brewster study wasn't a statistically significant lead. You shouldn't read it as a settled ranking.

The narrow answer: ChatGPT has strong Spanish medical results here. There isn't enough in these findings to name it the overall winner for your website, schoolwork or workplace documents.

Where DeepL fits

DeepL is harder to place using this evidence. No independent medical study of its Spanish was found. DeepL's own June 2026 blind tests covered 18 language pairs, but those are company tests, not the same evidence as the independent medical studies above.

That's an evidence gap. It isn't proof that DeepL translates Spanish worse.

Its free web translator allows 50,000 characters a month. If that fits the amount you need to translate, you can try it on your own material without treating its position in this comparison as settled.

For a business website, there's also the question of what happens to the code inside your text (separate from Spanish accuracy). Translinga, made by Bitgate for Shopify stores, WordPress sites and apps, removes Liquid tags, HTML and placeholders before translation. It checks replies tag by tag and retries any string returned with a missing tag. That's a workflow feature, not evidence that it wins on Spanish accuracy.

When you still need a human

For high-stakes medical instructions, don't rely on machine translation alone. That's the advice from the Kong study, even with its high Spanish accuracy results.

If you're choosing for work, school or a business website, the studies here can't tell you exactly when human review becomes necessary. They didn't test those uses.

Human translation isn't an error-free benchmark, either: professional translators had clinically significant errors in the Brewster study. For health information, the question isn't just which tool has the highest score. You still need a human to check the instructions you'll rely on.