The 5 best free translation APIs for language translation

A great product and clever marketing aren’t enough to reach global customers. You need to speak their language.

Enter translation APIs. These powerful localization tools integrate into your website and software, bridging language gaps to help you connect with international audiences. However, finding the right translation solution—especially one that fits your budget—isn’t easy.

Free translation APIs are a great starting point, but they often have limitations that may hinder your business as you scale. This guide will list the top free translation APIs and compare their features to help you find one that fits your business needs.

What is a translation API service?

A translation API is a service that enables instant translation into multiple languages, connecting your app or website to the world and opening doors to multilingual expansion. It allows you to offer seamless support to your global audience without relying on manual translators. APIs for language translations use a combination of natural language processing (NLP), machine learning, and even human expertise to ensure they’re as accurate and context-aware as possible.

Machine translation (MT) APIs help businesses reach global goals by simplifying localization and accelerating translation processes. Product managers use them to drive multilingual adoption and enhance customer satisfaction. Unlike sluggish traditional translation solutions, APIs enable rapid innovation cycles that align products and marketing materials with dynamic customer needs.

If you’re looking for an even more advanced solution, try Smartling’s REST API. Coupled with its industry leading Translation Management System (TMS), It offers seamless integration, supports file and text translation alongside state-of-the-art MT API capabilities, ensuring security and quality at scale. 

Watch the demo video below to see Smartling's REST API in action.

The 5 best free translation APIs 

Free translation APIs are a great way to dip your toes into multilingual content, but they’re often limited compared to paid solutions. Try these free options if you want to explore cloud-based translation services without straining your budget:

Google Cloud Translation API

Cloud Translation is Google’s free translation API. It’s an invaluable tool for businesses looking to expand globally, improve customer service, or create multilingual content. It easily integrates into your apps and offers real-time conversion with automatic detection for 249 languages.

Although Google’s API works well for general text, it may fall short with more complex or industry-specific terms.

Pricing is pay-as-you-go after the first 500,000 characters per month, so monitor your usage as you scale up.

DeepL API Free

DeepL is known for its accuracy and ability to handle more natural language nuances, making it a fast favorite in the machine translation community. The API offers impressive quality, especially for complex sentence structures. Additionally, it can switch between formal and informal tones—a nice touch for businesses with varied content needs.

Despite its high quality, DeepL falls short of Google Translate in range. The system only supports 30 languages and offers fewer integrations than other competitors.

DeepL is free for up to 500,000 monthly characters, with paid plans for higher usage.

Amazon Translate

Amazon Translate is designed for real-time, high-volume translation tasks. It supports over 70 languages, making it scalable for businesses with multilingual content needs. This flexible system can also translate text in numerous file formats, including Microsoft Word, PowerPoint, and Excel.

However, Amazon Translate lacks the nuance of human translation. It’s great for bulk text but might struggle with more specialized terminology.

Amazon Translate offers 2 million free characters per month for one year, with usage-based pricing beyond that point.

Systran

Systran’s translation API is well suited for precise terminology, making it ideal for businesses in the legal, technical, and financial sectors. The service also allows customization for unique language needs.

Downsides include a high-effort configuration process for custom uses and just 55 languages—limited support compared to other APIs.

Systran’s API is free for the first 500,000 characters with a 14-day trial. Premium plans offer more flexibility and additional volume.

Microsoft Translator API

Microsoft Translator is a cloud-based translation web API that supports 179 languages. It’s customizable and ideal for applications that require multilingual support. The same service is free within several Microsoft products, including Office, SharePoint, and Viva Engage, making it a versatile choice for product, support, and communication teams.

Like Google Translate, Microsoft’s API can become expensive as you scale. It’s also less customizable for brand-specific terminology.

The service is free for up to 2 million monthly characters, with pay-as-you-go pricing for each additional million characters.

Bonus: Smartling 

Although Smartling’s REST API service isn’t free, it stands out for its high-quality translations at a low overall cost, as well as extensible endpoints for high levels of customization. Free APIs are appealing but often have reduced functionality and language restrictions. Conversely, Smartling provides a more scalable solution for fast, high-quality translations. 

Smartling’s API lets developers easily integrate both machine and human translations into any app. By combining AI power with native expertise, Smartling doesn’t just translate—it fully localizes content to connect with diverse audiences. You also get real-time updates, translation management, and support for custom glossaries.

Plus, the onboarding process is quick. Smartling’s team ensures you’re up and running in 30 days or less.

Comparing text translation API pricing across top providers

Although some free services translate text at higher volumes, they may not scale adequately or serve your organization’s needs. Investing in a strong, AI-powered solution like Smartling is the best long-term strategy for businesses seeking professional, polished machine translations that resonate with global audiences.

Use this simple side-by-side comparison of the best translation APIs to identify your ideal service:

Scale efficiently with Smartling API 

Although free APIs can help with basic translation needs, they suffer from restricted scalability, limited language support, and the inability to integrate specialized industry terms or brand language. These shortcomings hinder your ability to provide high-quality, localized experiences as your business grows. 

That’s where Smartling comes in. With advanced machine translation capabilities, Smartling’s API offers fast, accurate translations that scale seamlessly as your global presence expands. Unlike free tools, Smartling’s platform integrates effortlessly into your workflows, giving you the flexibility to handle large projects.

Want to learn more before you commit to a translation provider? Check out our free eBook, “What to Look for in a Translation Solution,” and discover the features you need to take your global strategy to the next level.