Top 18 Translation Service Provider APIs

Top 18 Translation Service Provider APIs

Are you looking for a translation API to use in your new project? We curated a list of the 18 most popular translation service providers’ APIs available on the market. Maybe you’ll find a match!

Translating your content online hasn’t ever been easier than now. 🗣 Considering that content marketing is becoming increasingly important, the need to have this content translated into different languages is also increasing. This is where a Translation Service Provider (TSP) API enters the scene. 💡

📄 In this article, we’ll explain what is a translation API to translate and localize your content seamlessly and list 18 of the most popular translation APIs.

🤔 What is a Translation API?

A translation API is a software interface that developers can use to connect their own software with another application that can translate any text content.

That comes from the definition of an API:

API stands for Application Programming Interface. API enables applications to exchange data with each other. 📲

Many TSPs use a combination of machine learning algorithms and human capabilities to help businesses translate their content.

📝 List of Translation API Providers

We’ve collected some of the most advanced translation APIs for you to use in the list below.

Google Translate API

Google Translate is probably the most popular machine translation engine in the world. And when it comes to translation service providers, everyone would head to the big G.

The Google Translation API pricing is distributed into four tiers: Translation API Basic, Translation API Advanced, AutoML Translation, and Media Translation API. The first 500,000 characters are free, and the Basics package starts with prices as low as $1.5 per 575,000 characters.

Source: Google Cloud

The Google Cloud Translation API can be integrated easily by developers to make the production of accurate translations automatic and practical.

Google Translate is integrated inside Localazy and available on the Autopilot plan and above.

However, the API runs on machine translation and doesn’t understand the context in which a word or idiom may be used. The result can lead to funny and often embarrassing results and, in worse cases, legal troubles. But the best part about it is that it offers many integration options.

Amazon Translate

Usually, talking about the translation tech without mentioning Amazon wouldn't make sense. The company has launched its tool, Amazon Translate, which functions on Neural Machine Translation (NMT) algorithms to help produce quality translations. Their API accepts materials in several formats, including Excel spreadsheets, Word files, and PowerPoint presentations.

Source: AWS

Amazon Translate is also another machine translation engine that's available at Localazy. And the best thing about it is you can use it on the Free plan!

Unlike traditional translation services that rely on statistical algorithms and rules, Amazon implements deep learning, which tries to mimic how the human brain functions to deliver more natural translations. Also, the API seamlessly integrates the tool whenever you need it. Amazon Translate allows you to translate website content, chat messages, or emails.

Yandex API

Yandex launched its translation service in 2011, and since then, it has gone through continual enhancements. There are plans for both small and big companies as well as individuals, and its services include over 100 languages. Users say that Yandex’s pricing is more affordable than Google Translate API’s, which gives it an advantage.

Source: Yandex Translate API

However, Google Translate offers twice as many languages as Yandex (200+), which might be a dealbreaker. The service is used to translate both web pages and text materials. It does this by relying on a neural machine translation algorithm that analyzes the translated texts and builds dictionaries for each word which are then used to aid in the quality of translations.


If you are searching for a translation service that goes deeper into the intricacies of a language and has made headlines for beating other popular translation engines like Google with its accuracy, DeepL is the one. The statistics that compare it with other translation services offered by Facebook, Microsoft, and even Google Translate show that the difference is enormous.

Source: TechCrunch

What’s more exciting is that the DeepL Free translation API offers the option to translate up to 500,000 characters for free.

DeepL is the third engine built-in to Localazy. Enjoy some of the best machine translation engines with the Autopilot plan!

Source: DeepL Translator API

The formats you can translate using DeepL API include Word documents, PDFs, PowerPoint presentations, and HTML files. As in many other translation services, it comes with the capability to detect languages, which means that you’re able to upload a file, and it will detect its language instantly.

Microsoft Azure Translator API

Searching for a powerful translation engine that doesn’t take much work to set up? Our fifth alternative is the Microsoft Azure Translator API, which enables you to translate text between over 100 languages without much effort and is easy to integrate. You can choose between one of the three features that it offers.

Microsoft Azure Translator is the fourth (and at this time final) engine included with the Localazy Autopilot plan.

Source: Microsoft Azure Translator API

Depending on your situation, you may opt to translate documents and texts or build your own models to use the translator API however you want. Microsoft uses neural machine translation to power its translation services. It caters to a wide variety of industries, such as call centers or agents who need to speak with customers who belong to different nationalities.


You might have used the iTranslate on your phone for on-the-spot voice translations when speaking to a stranger. The handy mobile app supports over 100 languages. However, you’ll be able to use only about 50+ languages and dialects in their API integrations.

Source: iTranslate API

The iTranslate API supports text translations and ensures your data is kept safe by not keeping any records of it after it’s translated. Snap Inc recently announced that they were integrating the iTranslate API for their Lens Studio to provide AR developers with the capability to build multilingual lenses.


Another growing company that works majorly with large enterprises is Lingvanex. Their machine translation API is quite diverse and affordable for both consumers and businesses. Working with confidential data could get out of control quickly, and that’s why they enforce privacy protection according to the GDPR & CCPA policies.

Source: Lingvanex API

With prices starting from $5 per 1 million translated characters, Lingvanex supports over 109 languages and multiple content formats, including web content, files, and text. Once you’re signed up on the platform, you’re rewarded with a free batch of 200,000 characters that you can use before starting to pay.


If you go online, you’re likely to find some negative reviews about the app from two years ago, saying that it is a bit slow even though it has all the functionalities that it promises. This CAT (Computer-assisted Translation) tool and its API were born in the heart of Greece, Athens, slowly catching the attention of big brands like Reddit and Coursera, which started working with it.

Source: Transifex

The platform doesn’t directly offer translations, but it matches companies and users with translators and takes care of the translation management process. You can rely on it to manage content for digital products such as videos, games, websites, and mobile apps.

However, most of its features come for a steep price since it’s designed for large enterprises. Localazy is a much more affordable alternative, and it's easier to get started with it, as this Capterra comparison clearly concludes.

Smartling Translation API

This company has quite a reputation in the industry. Large-sized companies like Shopify and SurveyMonkey have chosen Smartling to manage their translation processes. Offering a CAT API, the platform comes in handy for translation services. You can order translations from professionals or use machine translations.

Source: Smartling

Their pricing isn’t cheap. It starts from $200 per month, and they don’t even offer a free trial or free version for new users.

Try Localazy for free. See what's included in the Free plan.

Even though Transifex offers complete translation management, Translation Memory (TM), CAT tools, and an API, they lack some of the essential localization features, such as activity dashboards and commenting.

Unbabel Translation API

Unbabel is the next translation provider on our list. It was founded by Vasco Calais Pedro, an academic interested in Social Network Semantic Analysis and Big Data and a Ph.D. holder in Computer Science. The platform offers support in over 30 languages and connects its users with human editors while providing a machine translation API at their disposal.

Source: Unbabel

Recently, they acquired another startup, Lingo24, which uses AI to translate content en masse. Major brands like Udemy and Microsoft have been using their services to empower their customer support teams to communicate with multilingual customers. However, Unbabel doesn’t offer a free trial version (unlike Localazy) and charges its users per feature.

Localazy translation API

Localazy API is a favorite way of integrating software products with the automated localization platform Localazy. It was launched in 2021, fresh with insights from the localization market and Localazy users, and it's equipped with powerful features that enable you to manage your translation projects at Localazy programmatically.

The Localazy API is organized around REST with predictable resource-oriented URLs, accepts JSON-encoded request bodies, returns JSON-encoded responses, and uses standard HTTP response codes, authentication, and verbs.

Source: Localazy Translation API

Localazy API offers endpoints to import content for translation, download translations, manage source keys in the project, and link source keys together to solve duplicity issues. You can also upload screenshots and manage glossary terms to ensure good context for the translators working on your Localazy project.

The Localazy API is continuously improving, and we are carefully listening to our user's feedback to enhance and automate their localization workflows.

Learn all about the Localazy API in the documentation.

And as said earlier, Localazy combines four machine translation engines inside one platform. So you’ll be able to use Amazon Translate as a free option and browse through suggestions from DeepL, Google Translate, or Azure Translate on the Autopilot plan and above.

TIP: We’re maintaining the @localazy/ts-api library, which wraps all of the Localazy API resources.

You can also read articles about the API on the Localazy blog:

Systran Translate API

Available to companies and individual developers needing to translate content across their projects, the Systran Translate API is pretty flexible to use. It allows you to translate both external and internal applications easily and offers the proper tools to tackle different types of content, including videos and images. It supports over 50 languages powered by artificial intelligence.

Source: Systran Translation API

The automatic translation API can easily detect languages, summarize documents, and easily translate online chats, web pages, or support tickets. Its translator API provides real-time translation and offers 500,000 characters in its free trial version that lasts 14 days.

Memsource API

Memsource was founded in 2010, providing a wide set of tools in its CAT API, including translation memories, integrations with translation management services, and desktop and browser versions.

In September 2022, the company announced its new identity with Phrase, another well-known localization software acquired by Memsource in 2021, thus renaming its services under Phrase name. That's why their brand is mentioned often in Memsource API documentation.

Source: Phrase

The Translation Management System (TMS) helps you with the translation management of website assets, file documents, and translators. You can access the platform through your mobile device and benefit from its machine translation engine.

POEditor API

The POEditor offers an automatic translation API that complements your translations via machine translations which can save a lot of time in large projects.

Source: POEditor

Their free version offers around 1,000 strings but doesn't include a Translation Memory (TM). The paid plans start at $14/month, and apart from using API, POEditor can be easily integrated with Bitbucket, VTSTS, and GitHub, among other technologies. It also integrates with Microsoft Teams and Slack to support communication during localization.


Libretranslate offers an open-source. self-hosted, machine translation API that focuses on providing high-quality translations and keeping your data safe. Supporting over 100 languages, this open-source machine translation API is practical to some extent. What's more exciting about it is the capability of the API to work offline as well.

Source: Libretranslate

Libretranslate provides self-hosted data services and allows you to use it even in production by utilizing an API key.

Unlike most translation service providers, the API doesn't rely on translation engines like DeepL, Amazon, or Google, but it uses the Argos Translate library, which is open source and might pose some accuracy issues at times. However, you can provide feedback to their production endpoints to suggest improvements.

Translated API

Translated machine translation API supports a wide range of file formats and an impressive number of 194 languages. Whether you're a developer or a company, their services span from real-time progress monitoring, quality assurance, and the option to add external translators to the project easily.

Source: Translated Translation API

The company mainly serves enterprises like Airbnb and has managed translations for over 260k clients so far. Their services aid marketers with Google Ads translation and subtitling while providing an efficient API. On top of that, they offer a free migration plan and a customized extractor to pull content from your data.

IBM Cloud API Language Translator

The IBM Cloud API Language Translator translation models allow you to customize the glossaries and terminology while translating content. The machine translation API provides different character sets and language pairs to help make your web apps multilingual.

Source: IBM Watson Language Translator

The level of customization is impressive since you're allowed to personalize the domain of the content you're translating further into corpus-level customization. Implementation is done with an easy API call. API

With customers like Adcash or Slidepeak, the Translate API offers both services from both human translators and machine translations (a combination that we provide through our Continous Localization Team).

Source: Translate API

The company offers support from human translators in over 70 languages and machine translations in over 90 languages. The service is used for customer service tickets, among others, and can immensely help reduce the costs of hiring multilingual agents. You can also use the API to translate web content, apps, and documentation.

✔️ Conclusion

Did you find your favorite? Are you missing any from the list? Let us know in the comments. Or jump straight in and try the Localazy API to localize your next project in a hassle-free way.