Machine Translation vs Human Translation: Why AI Is Not Enough

DeepL, Google Translate, ChatGPT: these tools have become remarkably capable across a wide range of tasks. But for contracts, official documents and high-stakes content, they remain inadequate and potentially dangerous. Here is why, with concrete examples.

What machine translation tools do well

Let us be honest: the advances of neural machine translation (NMT) models are spectacular. For many use cases, these tools deliver genuine value.

• Quick comprehension of a foreign-language email: deciphering a message from an overseas partner in seconds
• Browsing foreign websites: grasping the essentials of a page in an unfamiliar language
• First draft of a non-official document: obtaining a working base that a human translator then refines
• Competitive intelligence and foreign press: quickly understanding articles or reports in other languages
• Translation of repetitive and structured content: simple product catalogues, data lists, factual tables

DeepL is generally recognised as the best consumer-facing machine translation tool for European languages. ChatGPT (GPT-4) excels at reformulations and adaptations. For informal personal use, they often suffice.

The fundamental limitations of machine translation

Despite their progress, automated tools have structural limitations that even the best models do not fully overcome.

1. The absence of legal and contextual understanding

A machine translation tool translates words and grammatical structures. It does not understand the legal meaning of a clause, nor the legal implications of a terminological choice. Terms such as "legal representative", "apparent authority", "force majeure" or "termination clause" have precise meanings in Belgian law that do not necessarily correspond to their literal translation in another language.

2. Hallucinations and silent errors

AI models such as ChatGPT can "hallucinate": inventing plausible but false information. In the context of a contract, an official deed or a medical certificate, fabricated information can have serious consequences. These errors are all the more dangerous because they are often imperceptible to a non-expert.

3. Handling of proper nouns, dates and numbers

Automated tools regularly make mistakes with foreign proper nouns, reference numbers, dates in unusual formats and specialised technical terms. In a birth certificate, a misspelled name can invalidate the document.

4. Lack of terminological consistency

In a long document (15-page contract, complete medical file), machine translation may use different terms for the same concept from one page to the next. A human translator maintains a consistency glossary throughout the entire document.

5. "Rare" languages and regional languages

For less widespread languages (African languages, South-East Asian languages, Arabic dialects, Balkan languages), the quality of automated tools drops drastically. Even for languages such as Arabic or Chinese, dialectal and formal nuances are often poorly handled.

Concrete risks of using DeepL or ChatGPT for official documents

AI-assisted human translation: the best of both worlds

The reality in 2025 is that the best professional translators use AI tools as assistants, not replacements. This approach, called MTPE (Machine Translation Post-Editing), combines the speed of the machine with the judgement of the human translator.

At TranslateBE, our translators may use these tools for repetitive or factual segments, but every document is proofread, corrected and certified by a human expert. The signature and stamp of the sworn translator guarantee that the final document meets Belgian legal requirements.

Frequently asked questions (FAQ)

Is DeepL really forbidden for official documents?

It is not a question of a legal ban: administrations do not validate the translation method, they validate the sworn translator's signature. Without that official signature and stamp, your translation will be rejected. Discover the 5 most costly mistakes to avoid.

Can ChatGPT produce a certified translation?

No. ChatGPT cannot produce a translation with legal value. Only a translator who has sworn an oath before a Belgian Court of Appeal can officially sign and certify a translation. The linguistic quality of the tool is not the criterion: the legal status of the translator is what counts.

Is my data safe if I use DeepL Pro or ChatGPT?

DeepL Pro has a data non-retention policy for subscribers. OpenAI's ChatGPT stores data on servers in the United States. For sensitive personal documents (civil status, medical data, contractual information), we recommend avoiding these tools and using an agency that guarantees GDPR-compliant processing on EU servers.