Microsoft Translator Speech API

Microsoft Translator Speech API, part of the Microsoft Cognitive Services API collection, is a cloud-based machine translation service. The API enables businesses to add end-to-end, real-time, speech translations to their applications or services. Based on the industry standard REST technology, it can be used to build applications, tools, or any solution requiring multi-language speech translation regardless of the target OS or development languages.

Built for business, Microsoft Translator is a proven, customizable, and scalable solution for machine translation. Microsoft Translator technology powers speech translation features across Microsoft products, including live feature (preview), Presentation Translator add-in, and Skype Translator, and the Microsoft Translator iOS and Android Apps.

Speech translation is available from several languages. Speech-to-text translation is available from any of these languages and to all of Translator’s 60+ supported languages.

Try the Translator speech API – as a free open source app on You will first need to sign-up for a free 10-hour subscription.

Customizable speech transcription, translation, and synthesis (text to speech) is also now available in the unified Cognitive Services Speech preview. Speech combines the capabilities of the existing Translator Speech API, Bing Speech API, and Custom Speech Service (preview) into a unified and fully customizable service.  Learn more about this preview

How it works

Learn more about machine translation and how Microsoft Translator works.

Where can you use speech translation?

Microsoft Translator can be used to cost-effectively expand the reach and improve the experience across a variety of use cases.

Let’s look into a bit more details on a few of these use cases:

  • Live Presentation Translation: Translate a presenter’s speech into 60+ languages and enable users to follow live translations in the language of their choosing on their device. Additionally, presenters can save transcripts of their translated presentation.
  • In-Person or Remote Translated Communications: Use Microsoft Translator live feature in the Translator apps or web browser for in person live translated conversations and Skype Translator for remote conversations.
  • Customer Support: When your Call Center is experiencing an abnormally high-volume of calls, the integration of Microsoft Translator speech API into your infrastructure will add extra coverage for support. Or if there are special events that cause an influx of foreign language speakers into your customer service area, Microsoft Translator can extend your language offering (sporting/cultural events, tourist season, etc.)
  • Business Intelligence: Analyze your audio files by translating them into searchable text for your business decision makers to provide insights on sentiment analysis, customer service call logs analysis to identify trends on issues or identify early or new problems.
  • Media Subtitling: Provide automatic close captioning and subtitling in 60 languages for your live or recorded media events: webcast, broadcasts and when you’re offline use Azure Media Services.
  • Multi-Lingual AI Interactions: Enable natural multi-lingual interaction with your AI powered solutions by integrating Speech translation in the experience.

Why Choose Microsoft Translator for your Project?

Built for enterprise
  • Proven solution for global enterprise customers
  • Growing, high-quality offering of languages
  • Works across devices and operating systems
  • Adapts to enterprise workflows and products
  • Running on Microsoft Data centers: Scalable to support large scale applications such as Skype Translator
  • Free for small volumes up to 10 hours per month, discounts for larger volumes and enterprise agreement customers

Customer Implementation Examples

  • Speech API Blog Announcement
  • Tele 2 of Sweden, a leading mobile operator with more than 15 million subscribers in over 15 countries, integrated Translator into their PBX to support real-time phone calls translations on their cellular network.
  • LionBridge (Boston, MA), a language service provider and Gold Level Translator partner, developed an integrated video subtitling solution.
  • ProDeaf, an application vendor specializing in developing technologies to support the hard-of-hearing and deaf communities, integrated the new API into their sign language avatar app to enable multi-lingual support of speech to sign scenarios.

Try out the speech API with our open source Speech Translator app, on GitHub.

Get Started

Customization using Cognitive Services Speech preview

You can now use the speech to text, speech translation, and text to speech services with the same subscription to the Cognitive Services Speech preview. Using the Cognitive Services Speech preview, these three individual services can be customized using the preview of the new custom speech, translator and voice features.

Custom Speech (Speech to Text, Speech Transcription)

Convert spoken audio to text with default or custom models tailored to specific vocabulary or speaking styles of users (language model customization), or to better match the expected environment, such as with background noise (acoustic model customization). Speech to text technology enables a wide range of use cases like voice commands, real-time transcriptions, and call center log analysis.

Learn more

Custom Voice (Text to Speech, Speech Synthesis)

Bring voice to any app by converting text to audio in near real time with the choice of over 75 default voices, or with the new custom voice models, creating a unique and recognizable brand voice tuned to your own recordings.

Learn more

Custom Translator (Speech Translation)

Provide real-time speech translation capabilities with custom models based on neural translation systems that understand the terminology used in your own business and industry. These customized translation systems will then seamlessly integrate into existing applications, workflows and websites. Given the appropriate type and amount of training data it is not uncommon to expect gains between 5 and 10, even 15 in some instances, BLEU points on translation quality by using Custom Translator.

Learn more

Cognitive Services Speech is currently offered as a preview. For speech translation requiring a service in General Availability, developers should continue to use the Microsoft Translator Speech API.

Learn more

This service is part of Microsoft Cognitive Services

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