If you’ve read the news lately, you’ve probably heard that AI translation technology is advancing fast. Large Language Models (LLMs) like ChatGPT, Claude, and Gemini are surprisingly good at capturing tone, nuance, and intent in translations. Research from MIT says that LLM translations “have shown impressive capacity and competence” in generating fluent text.  

We ran side-by-side comparisons using common translation challenges to see how these LLMs perform in real-world business scenarios. The results were eye-opening: while each model showed strengths, they had key differences in accuracy, fluency, and speed.

In this post, we’ll explore the top 3 LLM translation tools and how to integrate them into localization workflows for your business.

Why Translations from LLMs Aren’t Enough

As eBay’s Silvio Picinini puts it: “Language AI has the potential to make translation more efficient, accurate, and accessible.” LLMs have changed the game for translation; they understand tone, intent, and cultural nuance. But they’re not perfect. 

That’s why companies like Mozilla still rely on human translators to guide and review LLM translation output. It’s faster, but accuracy and brand integrity still require a human check.

But speed and nuance aren’t the only concerns. There are other limitations that businesses need to consider.

Fluency ≠ accuracy

LLMs are remarkable at human-like AI translations, but a translation that sounds good can still be completely wrong. In high-stakes content like legal docs or product UIs, even a small error can confuse users or put your brand at risk. 

Limitations for file uploads

Uploading files like HTML for an LLM to translate doesn’t always work well. Large file sizes, multiple files, or complex content can reduce the accuracy of any model’s output. While LLMs are powerful, they still struggle with intricate documents and files.

Privacy concerns

Most LLM users don’t realize how complex data privacy becomes behind the scenes. As these advanced models power more everyday tasks—from translating content to generating code—the security risks of unauthorized data sharing, misuse, and personal exposure are growing fast.

The problem of scaling for business

No one can argue how easy it is to paste a quick phrase into ChatGPT and get a fluent translation. But scaling is different—what about multiple landing pages, files, or mobile apps? LLMs alone don’t scale well to fit complex business needs.

The 3 Best LLMs for Translation in 2025

 “LLMs have the potential to be transformative technologies for globalization... their broad applicability to natural language tasks means that they perform well for translation, especially for high-resource languages. -Microsoft

Whether you're building multilingual apps, automating workflows, or localizing a marketing site, LLMs can help, but they’re best used as a supplement. 

In 2025, the Localize Team tested ChatGPT-4, Claude 3, and Gemini 1.5 to see how they compare.

Testing the Translation Skills of 3 Top LLMs:

Make the Most of LLM Translation with Localize

LLMs are powerful, but choosing the right one and managing it yourself isn’t always the best path. Especially when translation accuracy and quality matter.

Localization takes more than a smart model. It requires the proper infrastructure, workflows, and quality controls.

That’s where Localize comes in.

Localize can help you tap into the power of LLMs without the complexity of managing models, infrastructure, or quality controls on your own.

The Competitive Advantages of Localize AI

Localize helps you move faster, translate smarter, and scale globally without the usual bottlenecks. Our AI-first workflows take the guesswork out of localization and deliver clean, accurate translations in record time.

Fast, Automated Translation—With Human-Level Quality

Localize integrates with industry-leading AI tools to instantly deliver high-quality translations.

• Always-on translation: Translate your entire website in minutes. Any updates or new content? Localize detects and submits them for translation automatically.
• AI-enhanced optimization: Use built-in LLM features to choose the best phrasing, improve context, and shorten copy for better UX.
• Error-free results: Eliminate manual copy-pasting and reduce errors across every language.

Built for Any File, Format, or Front End

Localize adapts to your workflow, whether you're localizing a marketing campaign, mobile app, support content, or product UI. 

• Compatible with all file types: JSON, HTML, XML, etc. 
• Fits into your tech stack: Any web technology, CMS, mobile apps, or API. It works anywhere you can install a JavaScript tag.

Speed at Scale, Without Sacrificing Accuracy

Localize helps thousands of companies launch in new markets, faster than ever. 

• Lightning-fast time to market: Automate tedious translation tasks while keeping your team looped in for review.
• AI + human oversight: Blend automation with professional translators or internal reviewers to fine-tune results from top AI engines like DeepL.
• Time-saving workflows: Get more done with fewer resources.

Enterprise-Grade Security and Compliance

Localize was built with security, so you can translate confidently, even if you work with sensitive or regulated data. 

• A commitment to data privacy: No sharing of customer data—ever. We don’t use customer data to train AI models.

• Unbeatable security compliance: Certified by the Cloud Security Alliance (CSA), HIPAA, and SOC 2.

Final Thoughts on LLM Translation

LLMs are changing how businesses approach translation. But even the best AI can’t replace the infrastructure, context handling, and quality control that localization demands.

Localize bridges that gap. We combine the power of AI with the oversight and workflows teams need to move fast and stay accurate. Whether you're translating a single site or scaling to dozens of new markets, we make it easy to go global confidently.

Ready to take the complexity out of localization? Let’s talk.