This page was last updated August 14th, 2020. We generally compile this comparison only from public or publicly derivable information. You can send updates and suggestions to [email protected].

At ModelFront, we're often asked for advice on the capabilities of the major machine translation systems.

Translation quality is highly subjective, and language-, domain- and application-specific. We don't find any single system to be the best in general across all those dimensions. We recommend running a good evaluation on multiple systems with your actual data.

But as important as raw quality - and often a decisivie factor on effective quality - are the features and limitations of each API.

For example, Google Translate supports German and French, and customization. But did you know that Google Translate doesn't yet support customization for pairs like German to French? That's because most APIs still translate via English. And DeepL now supports basic customization with its glossary feature, but its not yet available in the API or apps or plugins that connect to the API.

Language coverage varies a lot even for basic support. If you want to translate between Cantonese and Mayan, or Portuguese and Brazilian Portuguese, you'll have to use Microsoft or DeepL. But if you need Yakut, Udmurt or Papamiento, there's only Yandex.

Here's our current list of the most popular self-serve translation APIs with public per-character pricing.

Languages Customization Context Pricing

for 1M chars Google

Translate API 108 terminology



AutoML,

to and from English only $20

$80 for custom LingvaNex

Translate API 105 $5 Yandex

Translate API 93 terminology



custom models

in private beta $6

₽447 Microsoft

Translator Text API 73 terminology



Custom Translator,

to and from English only,

limited pairs $10

$40 for custom Amazon

Translate API 54 Custom Terminology $15 ModernMT

API 46 terminology



customization for all pairs



real-time learning document-level $15

$50 for real-time learning

IBM

Watson Language Translator 39 terminology



custom models $20

$100 for custom Baidu

翻译API 28 terminology



custom models



vertical-specific models ¥49

custom unlisted DeepL

API 11 neighboring lines €20 Alibaba

Machine Translation 15

limited pairs commerce-specific model $33

Language counts consider the listed languages, no matter how similar, and assume essentially all pairs of those languages are supported unless otherwise noted.

Pricing considers the paid rate at moderate volume, not free quota or volume discounts, nor prepaid or subscription discounts. Most of the APIs offer free quota, and charge small additional fees for training custom models and keeping them deployed. There is also continued widespread unpaid use of unofficial APIs based on reverse-engineering consumer translation applications.

Some systems use different architectures and even approaches for different language pairs or content types.

For more details, please see the documentation of each API.

Other machine translation APIs

There are other self-serve APIs to consider, notably those from Naver, eBay, Tencent and Youdao. There are also APIs like the Intento and the Rakuten RapidAPI that aggregate many translation APIs and more.

Other machine translation features

There are other features to consider, like locale, formality, data privacy, language identification, HTML and template translation, input correction, transliteration, speech input, latency, batching, offline models and on-prem deployment, that are out of the scope of this comparison for now.

For example, Google Translate produces French mostly with formal vous, Parisian French word choices but Canadian French punctuation. If you want informal Canadian French out of the box, you'll have to make some compromises - none of the major APIs produces it by default.

Other machine translation providers

SYSTRAN, Unbabel, Lilt, Tilde, Omniscien, KantanMT, TextShuttle, Globalese, Iconic, AppTek, SAP and more train custom machine translation, but do not offer a self-serve API with public per-character pricing. SYSTRAN offers an open-source library, OpenNMT.

Other machine translation players

Apple, Facebook and Rakuten have their own machine translation deployed in their own consumer platforms, but do not offer an official API. Facebook does offer an open-source library, Fairseq, and pre-trained models.

To the best our knowledge at this time, many others with machine translation in their platforms, like Twitter and AirBnB, as well as translation providers and CAT tools like Lionbridge and SDL, use the APIs listed above or on-premise deployments of other providers and do not develop their own machine translation from scratch.

Machine translation libraries

Many major machine translation providers also offer open-source libraries and even pre-trained models.

Owners Users Fairseq Facebook Marian NMT Microsoft Unbabel, Rakuten, eBay, Tilde, Project Bergamot, Opus-MT ModernMT

based on Fairseq ModernMT OpenNMT SYSTRAN, Ubiqus seq2seq Google Sockeye Amazon

Pre-trained machine translation models

Opus-MT offers pretrained Marian NMT models for many language pairs. They are also available via Hugging Face.

Facebook offers pre-trained Fairseq models for a limited number of languages.

August 2020 - LingvaNex

LingvaNex launches their translation API with more than 100 languages.

August 2020 - Microsoft

Microsoft launches Odia (Oriya), Dari, Pashto and Sorani and Kurmanji Kurdish, bringing its total number of languages to 77.

June 2020 - Microsoft

Microsoft launches Kazakh, bringing its total number of languages to 72.

April 2020 - Microsoft

Microsoft launches Marathi, Gujarati, Punjabi, Malayalam and Kannada, bringing its total number of languages to 71.

April 2020 - DeepL

DeepL launches Brazilian Portuguese in addition to Portuguese, joining Microsoft in offering two varieties as a target language. In contrast, Google's only option is Brazilian Portuguese.

March 2020 - ModernMT

ModernMT announces free machine translation for April and May, unlimited other than by its hardware constraints.

March 2020 - Yandex

Yandex launches Yakut, bringing its total number of languages supported to 97. However it's one of 4 languages not yet available in the API.

March 2020 - DeepL

DeepL adds Chinese and Japanese, its first non-European languages, bringing its total number of languages supported to 11.

February 2020 - Google

Google adds Kinyarwanda, Odia (Oriya), Tatar, Turkmen and Uyghur, bringing its total number of languages supported to 108.

January 2020 - Yandex

Yandex launches Chuvash.

January 2020 - Microsoft

Microsoft launches Irish Gaelic.

October 2019 - ModernMT

ModernMT launches human-in-the-loop, document-level context and context adaptation.

Thanks

We're very thankful to all who have contributed to this comparison.