In this post
On this blog, we have discussed many different translation services, from Google Translate and DeepL to AI translation tools and more. What we haven’t done so far is test how accurate these translation sites are compared to each other. So that’s the goal of this article.
Below, we are looking at some of the most popular online translation services and sites and examining which produces the best results. At the end of this post, we want you to feel empowered to pick the right tool for whichever job you have in mind.
How Accurate Are Translation Websites? – Test Setup
This test will focus on translating to English from four languages: Turkish, German, Mandarin Chinese, and Korean.
Why those languages?
Because they are all languages I speak (with the exception of Korean) so I have a good level of confidence that I can come up with sensible testing material and judge the accuracy of the results. For Korean, this isn’t necessary because we will only translate to it from English and then back again to test how well our candidates retain the meaning.
In addition, this testing pool covers a wide range of grammatical structures and language features. Turkish is an agglutinative language, Korean and Chinese both don’t even use the Western alphabet. The only language that’s from the same family as English is German. All of this should present a good challenge for our translation sites.
Translating Simple Sentences from Turkish to English
The first step involves translating fairly straightforward sentences from Turkish that include different grammatical features:
- Ali okula gider. → Ali goes to school.
- Dün sinemaya gittim. → I went to the cinema yesterday.
- Yarın çalışacağım. → I will work tomorrow.
- O kitap okumaz. → He/She does not read books.
- Sen kahve ister misin? → Do you want coffee?
- Nereye gidiyorsun? → Where are you going?
- Çocuklar parkta oynuyorlar. → The children are playing in the park.
- Annemin arabası eski. → My mother’s car is old.
- Ben kitap okuyorum ve müzik dinliyorum. → I’m reading a book and listening to music.
- Eğer erken gelirsen, birlikte yemek yeriz. → If you come early, we will eat together.
Aside from that, we are also trying out a number of sentences that include some characteristics special to the Turkish language:
- Evlerimizdekiler dışarı çıkmış. → The (people) in our houses have gone out. (agglutination)
- Ali sinemaya gitmiş. → (Apparently) Ali went to the cinema. (evidential past)
- Annesi çocuğa yemeğini yedirdi. → His/her mother fed the child. / The mother made the child eat his/her food. (causative voice)
- Yaptım. → (I) did it. (omission of object)
- Onun ne söylediğini anladım. → I understood what he/she said. (nominalization)
Chinese Idiom Translation
Chinese is very well known for its richness in idioms. They are one of the things that make translation difficult, so it’ll be interesting to see how our testing candidates deal with them. Here are the ones we’ll use:
- 对牛弹琴 (duì niú tán qín) → “Playing the lute to a cow.” (Means to waste time explaining something to someone who can’t appreciate it.)
- 入乡随俗 (rù xiāng suí sú) → “When you enter a village, follow its customs.” (Equivalent to “When in Rome, do as the Romans do.”)
- 骑虎难下 (qí hǔ nán xià) → “It’s hard to get off a tiger you’re riding.” (To be stuck in a situation you can’t escape from.)
- 狐假虎威 (hú jiǎ hǔ wēi) → “The fox borrows the tiger’s power.” (Bullying others by relying on someone else’s authority.)
- 塞翁失马 (sài wēng shī mǎ) → “The old man lost his horse.” (A setback may be a blessing in disguise, based on a famous story.)
Will it be good? Or will we witness more bad Chinese translations? Let’s find out together.
German Sentences Using Compound Nouns
My mother tongue, German, is famous for its ability to form very long nouns. Here are the examples we are going to use to find out how accurate our translation sites are:
- Wegen des Versicherungsgesellschaftsangestellten verzögert sich die Bearbeitung. → The processing is delayed because of the insurance company employee.
- In der Schienenverkehrsunfallstatistik gab es einen Rückgang von 8 %. → There was an 8% decrease in the rail traffic accident statistics.
- Der Luftqualitätsüberwachungsbericht wurde gestern veröffentlicht. → The air quality monitoring report was published yesterday.
- Wir diskutieren noch über die Arbeitszeiterfassungssoftware für das neue Büro. → We’re still discussing the working hours tracking software for the new office.
- Ihre Kreditkartensicherheitsnummer war falsch eingegeben worden. → Your credit card security number was entered incorrectly.
- Die Arbeitszeitnachweispflicht gilt ab dem 1. Januar. → The obligation to document working hours applies from January 1st.
- Der Klimaschutzmaßnahmenkatalog wurde gestern im Bundestag vorgestellt. → The catalogue of climate protection measures was presented in the Bundestag (German parliament) yesterday.
- In der Verbraucherzentralebeschwerdedatenbank wurden neue Einträge gefunden. → New entries were found in the consumer advice center’s complaint database.
Translate From English to Korean and Back
Finally, we will do one round-trip translation from English to Korean and back to English. The goal is to see how well our translation sites retain the original meaning. The opening paragraphs of The Hobbit by J. R. R. Tolkien will serve as the testing material.
This has the added benefit to allow us to test our candidates in literary translation (which is difficult in itself, especially for machines, because it needs a lot of context and nuance). In addition, we are translating English back and forth into a language that’s very different and one of the hardest languages in the world.
To make it more accurate, I’m copying the Korean translation, then inputting it into a new window of each site in incognito mode.
Grading the Results
Once everything has been fed into each of the online translators below, the results will be judged on the following factors:
- Accuracy: Is the meaning correct? Are any key details lost or added?
- Grammar: Is the output grammatically correct and natural in the target language?
- Style/Tone: Does it match the formality, intent, and voice of the original?
We’ll use a scale of 1-10 for every sentence individually, and calculate averages from there. Another thing we’ll examine is the usability of each service. It doesn’t matter if you get a super accurate result if it’s a pain to get there.
By the way, if you want to run your own test, you can find the material and testing results here.
Comparing the Most Accurate Translation Sites
After that long preamble, let’s find out which translation website provides the most accurate output.
1. Google Translate (9.7)
Google Translate might be the most well-known translation site—but is it the most accurate? The service offers almost 250 languages and dialects to translate from and into, resulting in thousands of available language pairs. Some of them are very rare, like Corsican, Maori, Yucatec Maya, and Jamaican Patois.
You can translate text directly online, upload images and documents for translation, or translate websites via overlay.
One factor that makes Google Translate very attractive is the price tag—it’s completely free to use. It also has a super easy interface. Just choose your languages at the top (or have Google Translate detect the source language), then paste your material on the left and receive the output on the right, complete with phonetic pronunciation if necessary.
You can also have Google Translate read things out for you, copy the translation with one click, start a Google search for the translated text, rate and share the translation, view your translation history, and save phrases for later.
Translation Accuracy
So, how accurate is Google Translate?
- Meaning: 9.5
- Grammar: 10
- Style/Tone: 9.6
- Overall: 9.7
As can be expected by one of the market leaders in machine translation, it does a pretty good job. All output was grammatically correct and mostly fit the style and tone of the original.
There were some smaller inaccuracies in the Turkish translations, such as picking present simple instead of present continuous. On the other hand, did pretty well with the Chinese idioms.
The thing Google Translate struggled most with was the Korean round-trip, which is to be expected. The result was still understandable but especially the second paragraph got a little convoluted.
Still, 9.7/10 is a solid rating to start with.
2. DeepL (9.5)
Another popular online translator, DeepL handles fewer languages than Google Translate (113 to be exact) but is known to be one of the most accurate translation sites. It works pretty much the same as its competitor—choose your languages, input text on the left, and receive your translation on the right.
To improve accuracy, you have the option to create a glossary. There’s also a dictionary to look up single words, and you can translate documents and use DeepL to edit or rewrite your text with the help of AI.
The online translator is free up to 1,500 characters, three documents per month, and 10 glossary entries. The Pro version starts at $8.74/month. It also offers features like choosing whether you want your translation to be formal or casual, setting up style rules and profiles, and refining your translations with AI.
Translation Accuracy
- Meaning: 8.8
- Grammar: 10
- Style/Tone: 9.6
- Overall: 9.5
DeepL achieves pretty good results as well. It, too, made a tense mistake in Turkish and had some smaller gaffes.
For the Chinese idioms, in an earlier version of this test, DeepL provided additional information about their meaning besides the literal translation.
This currently isn’t the case anymore, which is a shame. DeepL still did mostly a good job in the translation though.
Where the site was surprisingly accurate was the translation of The Hobbit opening. Especially the second half was very close to the original.
3. Bing Translator (9.6)
This is the online translation site by Microsoft, makers of the Bing search engine. It offers translation for a large number of languages, almost 180 to be exact. The usability is the same as earlier entries on this list: a field to enter text, drop-down menus to choose your languages, and a button to upload images for translation.
What stands out is that Bing Translate has an extra menu to choose the tone for your translation.
It also gives you the option to regenerate results with the help of AI for greater accuracy or fluency.
Translation Accuracy
- Meaning: 9.0
- Grammar: 9.9
- Style/Tone: 9.8
- Overall: 9.6
Despite the fact that Bing isn’t usually the first thing you think of when talking about online translators, it delivers surprisingly solid results. There were smaller issues at first, like the fact that is put “I did” in Turkish instead of “I did it.”
The possibility to have an AI-powered do-over really came in handy for the Chinese idioms. It added some much needed context and replaced some of the literal translation with proper English equivalents.
The round-trip translation was only alright, but it’s a difficult challenge.
5. ChatGPT (9.7)
ChatGPT is one of the most popular AI tools, but is it also among the most accurate translation sites? You can find out by simply pasting your source material and writing a prompt to say you want it translated and to what language. What’s important is that you specify the output format, for example, to make it easy to copy and paste.
It’s also possible to upload images to the chatbot and ask it to translate their content. It can even create new image versions with the translated text and yields pretty impressive results
Another advantage of using AI is that you can tell it to adjust the tone of its output or make iterative improvements to it.
How many languages does ChatGPT know? According to itself, it can translate “between dozens of major languages and many more less-common ones—well over 100 languages to varying degrees of quality.”
Usability wise, for text translation, ChatGPT is comparatively slow. In contrast to Google Translate or similar tools, where the result is pretty much instantaneous, you have to wait for the output to be generated. This is to be expected, but it does make a difference in user experience.
The free plan is limited in output per day. If you want more than that, paid plans start at $20/month.
Translation Accuracy
- Meaning: 9.5
- Grammar: 9.9
- Style/Tone: 9.6
- Overall: 9.7
ChatGPT is pretty good on the translation front. The simple sentences didn’t pose a big problem for it (which, to be fair, it also helped create).
Its translation of the Chinese sayings were also solid. In an earlier version of this post, it provided both literal translations and also explained the meaning behind them, which was really helpful.
Inexplicably it did not do the same in the latest test, even though context awareness is one of the main benefits of AI-pwered translation.
For example, it really helped ChatGPT’s scores while translating the book excerpts back and forth. Even though I told it to treat the Korean source material like an unknown text, the tool spit out the original passage from the book — complete with an em dash that wasn’t even in the Korean version.
6. Google Gemini (9.7)
As a tool not specialized in translation, Google Gemini comes with the same issues as ChatGPT. For the most part, that means a slower translation speed and the need to specify your desired output format. Yet, Gemini felt faster than ChatGPT overall.
Like its competitor, Gemini can translate images you upload to it and does a fairly good job at it. If you use its mobile app, the AI chatbot can even do live translation of any text you point your camera at.
Gemini states it can translate between over 70 languages in real-time. While it’s able to understand and process text in more than 100 languages, its performance is most robust across those most widely spoken.
There’s a free version with daily usage limits, which you should only run into for very long translations. If you want more, paid plans start at $7.99/month and the tool integrates with many other Google products you might be using.
Translation Accuracy
- Meaning: 9.5
- Grammar: 10
- Style/Tone: 9.7
- Overall: 9.7
The translation capabilities of Gemini are really good. In fact, it’s as good as its cousin Google Translate. Plus, unlike ChatGPT, it provided both the literal translation and an explanation for context for the Chinese idioms.
The first time I asked Gemini to translate the opening of the Hobbit from Korean, it instantly recognized the passage and spit out its original word for word.
I had to ask it to treat the Korean source material as if it had never encountered the text before, which made for a slightly less accurate, but still pretty good version.
7. Perplexity (9.9)
AI search engine Perplexity also has the ability to translate languages—thanks to the LLM working in the background. While that’s not its primary purpose, it’s still really good at it. Perplexity also has the ability to tell you the meaning of text in images, but it doesn’t translate visuals or do live translation.
What stands out most about this translation site is the speed. Out of the AI tools I tested, it was the quickest in its output.
Perplexity states that it can translate 100+ languages in practice, but the exact breadth of its skill depends on the language pair, the text style, and whether you want a quick draft or a more polished version.
Translation Accuracy
- Meaning: 9.7
- Grammar: 10
- Style/Tone: 9.9
- Overall: 9.9
With an almost perfect score, Perplexity is definitely among the most accurate translation sites. One of its biggest detractors was the sentence “Your credit card security number was entered incorrectly,” where it used “had been” instead. This was a common mistake but the switch in tenses really makes a difference.
While its literal translation of the Chinese sayings was good, in an earlier test, it also provided explanations for their meaning and how to use them, but not this time.
Perplexity, too, recited the opening lines from The Hobbit flawlessly from memory until told otherwise. In fact, it once refused to provide a translation on the grounds that it is copyrighted work. Still, its “non-remembered” version was also really good, which is why it scored so high in the test overall.
8. Systran (8.9)
Systran is one of the oldest translation companies and we have written an extensive review of their services. They also offer an online translation tool for over 50 languages. It allows you to translate up to 5,000 characters at once, free of charge.
The translation interface looks very much like other candidates on this list. Just paste your source material on the left, receive the translation on the right, and don’t forget to choose your desired language!
Translation Accuracy
- Meaning: 8.2
- Grammar: 9.6
- Style/Tone: 8.9
- Overall: 8.9
Systran did well for the standard translations. Where it struggled was the Chinese phrases, some of which it translated as “sing at a piano with cows,” “be unable to back down,” and “law of the jungle.”
The back-and-forth translation of Tolkien’s writing also gave it trouble and produced gems like, “Filthy, dirty, wet holes are full of worm tips and are not seething.” Sure, mate, couldn’t agree more.
Overall, a solid effort but definitely not among the most accurate translation sites in this test.
9. Reverso (8.4)
Reverso is a language learning portal that also has an online and desktop translation tool. It supports 28 languages for both direct and document translation. Besides that, you can find a grammar check, look up words in context, conjugate verbs, find synonyms, and much more.
The translation tool is free for a limited amount of text. If you want more, there’s a subscription starting at €6.49.
Translation Accuracy
- Meaning: 7.3
- Grammar: 9.5
- Style/Tone: 8.2
- Overall: 8.4
Reverso deals well enough with standard translation needs but showed some clear weak points in dealing with the Chinese idioms. It translated them as follows:
- “Playing the piano with a cow”
- “Follow the customs in the countryside”
- “It’s hard to ride a tiger”
- “Fox Fake Tiger Power”
- “Theon lost his horse”
While amusing, three out of five sentences scored zero points in the Meaning category. Overall not the strongest showing even if the grammar scores were pretty good.
10. PROMT.One (8.1)
This online translation and dictionary tool comes with the usual user interface and support for over 20 languages. You can also use it to find the meaning of words in context and conjugate and decline verbs and nouns.
PROMT.One is free to use though it only allows 5,000 characters at a time. It also offers a mobile app and desktop applications for offline text and document translation.
Translation Accuracy
- Meaning: 7.0
- Grammar: 9.3
- Style/Tone: 8.1
- Overall: 8.1
The translation accuracy is similar to Reverso. Standard and simple sentences don’t pose much of a problem. There were some smaller issues, like translating “I did it” as “I had it done” from Turkish.
The big obstacle were the Chinese translations. It scored zero for “Right, cow playing”, “Homesick”, and “Fox Fake Tiger.” What’s curious is that PROMT.One translated the last idiom as “Théon lost his horse,” just like Reverso. This begs the question: who is Théon? And why does he keep losing his horse?
One of the German sentences was also not correct, it used a rather pompous “shall apply” instead of “applies” or “will apply.” And then, the results of translating to and from Korean were also less than stellar, which is why PROMT.One scored the way it did.
11. OpenL (9.8)
OpenL is an AI-powered translation tool offering more than 100 languages. Besides direct text translation, it can handle documents, images, audio recordings, and websites. OpenL also has a range of other tools, including:
- Grammar fixer
- AI detector
- AI humanizer
- Text-to-speech tool
- Summarizer
The online translator allows you to choose different styles for your output, such as general, professional, medical, legal, etc. However, its free functionality is limited. You get 40 credits per day to try it out (one credit is one translation). If you want more, plans start from $8.90/month.
Translation Accuracy
- Meaning: 9.6
- Grammar: 10
- Style/Tone: 9.7
- Overall: 9.8
I have to admit, I had never heard about this translation site before this article. It makes my surprise at its quality and score even bigger.
Even the Chinese translations ended up really good, although it only provided literal translations without any explanation. OpenL only lost points for “The fox assuming the tiger’s might,” which leaves room for misinterpretation.
Aside from that, the tool also scored slightly lower in the English-Korean-English part of the exercise. But, I can only repeat myself, a really strong showing.
12. Lara Translate (9.3)
Lara Translate claims its newest model is as good as the top 1% of professional human translators. It’s not publicly available yet, so we have to settle for the current model, which is supposed to be close but not quite there yet.
The service can translate text in 200+ languages, convert documents, and act as a live interpreter. You can dictate your source material via microphone and have both input and output read to you.
An interesting option this translation site offers is the ability to pick different levels of translation — from faithful or fluid to creative. You can also add contextual information and the tool explains the choices it makes and proposes ways to clarify and improve the results. For example, it pointed out that some of the Turkish sentences are ambiguous because they don’t specify gender.
If you’re still unconvinced, you can even get help from human reviewers. There’s a free version for up to 5,000 characters per day. Paid plans come with translation memories and glossaries and start from $9.99/month.
Translation Accuracy
- Meaning: 8.8
- Grammar: 9.7
- Style/Tone: 9.3
- Overall: 9.3
Lara Translate did well for most of the standard translations. A bigger lapse was that it output “we can have dinner together” in the Turkish translation, instead of just “we’ll eat together,” which is a bit too much interpretation.
On the other hand, it did a really good job with the Chinese sayings, except for “Saiweng Loses His Horse.” While Saiweng is indeed the name of the old man in the story this saying derives from, this translation isn’t very helpful if you don’t know the context. It also had every word capitalized for some reason.
The literary translation at the end was pretty solid as well. Lara Translate even recognized that the English to Korean passage was from Tolkien.
Finally, it’s the tool on the list that has most improved since the last test. It initially scored an 8.7 and has since climbed up to a solid 9.3.
13. QuillBot (9.5)
The final of our more-or-less accurate translation sites is an AI tool for many language operations, including paraphrasing, grammar and plagiarism check, AI detection, and more. Ironically, something else they offer is an AI humanizer.
The translation feature supports 52 languages and dialects. Usage is as easy as most translation sites in this article, with a familiar interface. The free plan gives you 5,000 characters to translate, the premium offer without limits is $8.33 per month (billed annually).
Translation Accuracy
- Meaning: 9.1
- Grammar: 9.8
- Style/Tone: 9.6
- Overall: 9.5
Quillbot is another surprising entry. It was completely unknown to me before this test but scored really well. It made some interesting stylistic choices by inverting the order of subordinate clauses from the source material, but it was great at preserving the original meaning.
Something else that was impressive was its ability to adhere to the tone of the source material. It did so even for the Korean version of the Hobbit. A well deserved score.
On the other hand, there were two instances where its output included typos (“employe”) or single words simply tacked on to a sentence. Plus, one detail from the opening of The Hobbit (that the comfortable tunnel was “without smoke”) got lost somewhere on the way.
Additionally, the translation was quite slow. Quillbot had one of the longest waiting time of all the tools tested here.
So, What Are the Most Accurate Translation Sites?
And the winner is—drumroll—Perplexity! Speed, accuracy, preserving tone, it does it all. While the AI search engine is not quite as easy to use for translation as something like Google Translate or Bing Translator, the quality it delivers is top-notch.
As for the rest of the entries, with so many well-known names in the list, there were quite a few surprises, especially OpenL and Quillbot. In addition, DeepL scoring as low as it did was unexpected given its reputation.
AI seems to be one of the winning differences. Many of the highest scorers are LLMs or use one behind the scenes. This makes sense, as a lot of translation is about context and background information—something that straight translation tools don’t possess. Here are the results again in one handy-dandy chart.
| Tool | Meaning | Grammar | Style/Tone | Overall score |
|---|---|---|---|---|
| Perplexity | 9.7 | 10 | 9.9 | 9.9 |
| OpenL | 9.5 | 10 | 9.5 | 9.8 |
| Google Gemini | 9.5 | 10 | 9.7 | 9.7 |
| Google Translate | 9.5 | 10 | 9.6 | 9.7 |
| ChatGPT | 9.5 | 9.9 | 9.6 | 9.7 |
| Bing Translate | 9.0 | 9.9 | 9.8 | 9.6 |
| QuillBot | 9.1 | 9.8 | 9.6 | 9.5 |
| DeepL | 8.8 | 10 | 9.6 | 9.5 |
| Lara Translator | 8.8 | 9.7 | 9.3 | 9.3 |
| Systran Cloud | 8.2 | 9.6 | 8.9 | 8.9 |
| Reverso | 7.3 | 9.5 | 8.2 | 8.4 |
| PROMT.One | 7.0 | 9.3 | 8.1 | 8.1 |
Use TranslatePress for the Most Accurate Website Translation
Translation accuracy is also an important factor when it comes to converting your website to another language. It plays a role in user experience, multilingual SEO, and international marketing.
TranslatePress includes TranslatePress AI, which uses several sources for machine translation and automatically picks the most appropriate for your language pair to ensure the best translation quality. It’s part of every TranslatePress license, and you can use it with credits available through your account.
Plus, TranslatePress AI makes website translation quick and easy, too. Basically all you have to do is install the TranslatePress plugin and define your site’s default language plus at least one target language in Settings → TranslatePress.
After that, head over to Automatic Translation and use the drop-down menu to enable machine translation. Save your changes at the bottom.
TranslatePress will now automatically start converting your website to the chosen language(s). By the time you visit the front end of your site and use the language switcher, the translation is probably already finished.
This works for all WordPress content, including text coming from plugins and themes. Alternatively, you can choose to use Google Translate or DeepL for your translation.
Besides that, you have the option to refine translations by hand. For that, just click on Translate Site/Page in the TranslatePress settings or the WordPress admin bar.
You will land in a separate interface where you can simply pick content from the preview window and enter or edit the translation in the dedicated field.
This method also works to translate your entire website manually and for using translated or localized images.
Other TranslatePress Features
Aside from the above, TranslatePress offers many more useful features:
- Automatic language tags: The plugin adds hreflang tags for all languages to every page on your site. That way, they are more likely to appear in search results for the correct locale and language.
- SEO features: TranslatePress creates multilingual sitemaps to submit to search engines and works with most of the popular WordPress SEO plugins.
- Pro features: With a Pro subscription, you additionally get access to features like automatic user language detection, translator accounts, or navigation based on language. The included SEO pack that lets you translate your page URLs, SEO titles, meta descriptions, and other important SEO markers. Business and Developer licenses can also use different domains for each language.
You can start off with the free version of TranslatePress for one additional language. TranslatePress Pro offers three pricing tiers so you can find the right option for you.
Which Online Translator Will You Choose?
Picking the most accurate translation site depends on your specific needs, but our test revealed some great candidates. AI-powered tools like Perplexity and Google Gemini are leading the pack by offering not just accuracy but also the ability to explain context and nuance. This is something traditional translation tools struggle with.
On the other hand, for everyday translation needs, Google Translate remains a solid, free option with excellent usability, along with Bing Translator and even DeepL, despite the latter scoring lower than expected.
Finally, if you want an automatic, user-friendly, AI-powered solution to translate your website in no time, look no further than TranslatePress!
