In terms of the technical details, REST as the architectural style and Web/Internet as the API type lead the way.There are 129 RESTful APIs in the translation category and 29 marked as Web/Internet.
It’s no surprise to see that URI Query is the most common request format with 95 APIs using it. XML with 17 and SOAP with 16 come next. As for response formats, JSON leads the way, being used in 96 APIs, while XML appears in 56.
For reference here is a list of the most popular Translation APIs measured by user click-throughs to the provider site.
Google Translate - The Google Translate API is now in its second version. As part of Google's larger Cloud Machine Learning API family, the Translate API can translate text between thousands of language pairs. The Cloud Translation API lets developers programmatically integrate the service with third party sites and applications.
Merriam-Webster DictionaryTrack this API - Merriam-Webster has been producing language information including dictionaries, thesauri, and translation materials for over 150 years. The Merriam-Webster collection of APIs provide developer access to a variety of the company's most prominent reference works. Free access is provided to non-commercial websites and applications. Free access is limited to two reference works with a maximum of 1000 queries a day per reference work. Full access is available for commercial use.
ThesaurusTrack this API - Thesaurus is a web service providing search capability for synonyms in different languages. Thesaurus can be used by third party applications to retrieve the list of synonyms in English, Italian, French, German, Spanish and Portuguese.
SYSTRAN DictionaryTrack this API - The SYSTRAN Dictionary API enables users to search for the translation of words, with additional contextual information such as grammatical information, frequency of the meanings, domains and contexts, expressions and examples. Users can also create personal dictionaries and search within them.
ABBYY LingvoTrack this API - The ABBYY Lingvo API provides users with access to the largest collection of Russian dictionaries including 140 dictionaries across 15 languages. Categories include general, professional, thematic dictionaries and thesauruses. The API can be used to develop vocabulary games and quizzes, mobile apps and websites for language learning and eBooks. Additional use cases include collocations and pronunciation.
Microsoft TranslatorTrack this API - The Microsoft Translator API is a cloud based machine translation service. It lets users translate text, pictures, websites, documents and full conversations in over 60 languages within their websites and applications. Microsoft Translator Text API is part of the Microsoft Cognitive Services API collection of machine learning and AI algorithms in the cloud.