AI Translation from English to Vietnamese Translation

How good is AI translation from English to Vietnamese?

Two or more one-step solutions meet every Basic, Standard and Advanced requirement in Vietnamese.
The cheapest solution that meets every Standard requirement costs $16.82 per million characters, and the fastest takes 67 seconds per 1,000 words.

A solution is a model plus its harness: prompts, glossaries and other context, pre- and post-processing. It meets a quality level when it meets every requirement of the level.

Requirement	Description	Met when
Basic requirements for any company
General translation quality	Translation errors of every type, such as mistranslations, omissions and grammar errors, classified by type and severity following MQM, the industry standard.	No critical error, at most 3 major errors in the four test texts (3,034 words) and at most 20 errors per 1,000 words, weighted by severity (minor 1, major 5, critical 10).
Standard requirements adds the rules companies set for their content
Terminology	The approved translation of every glossary term, in any of its correct forms.	100% of the glossary terms. We test it in the 16 languages with a glossary, so it does not apply in Vietnamese.
Tone of voice	The formal register (quý vị or neutral terms) in every sentence in the second person or the imperative.	100% of those sentences.
Tags	Every HTML tag of the source, with its attributes, in the translation.	100% of the tags.
Unicode character integrity	Every character intact, with no corrupted characters and no letter from another script that only looks like the right one.	100% of the characters.
Locale conventions	The punctuation marks of the target language in place of the English ones.	No pass-or-fail bar. We report it as a share, because whether to localize punctuation is a matter of house style.
HTML entities	No HTML character code, such as the code for a quotation mark, that the source does not carry.	No added HTML entity.
Valid JSON	The translated JSON document still parses.	The document parses.
Spacing at tag boundaries	The spaces next to HTML tags stay as in the source.	100% of the tag boundaries.
Advanced requirements adds a requirement for some companies and use cases
Gender neutrality	A gender-neutral translation wherever the English source leaves the gender of a person open, as in “your manager” or “the expert”.	100% of the sentences that refer to a person.

Find English to Vietnamese translation solutions for your requirements

Pick a quality level, or your own requirements, bars and constraints, to see the shortlisted solutions that meet them in Vietnamese, with a column for each requirement you select. Under Optimize for, choose which of them comes first: the one with the fewest total errors, the lowest cost or the shortest time. Click a column heading to sort by it.

The shortlisted solutions on 12 models, with their Intento LQA results. Total errors per 1,000 words add the weighted general translation quality errors (minor 1, major 5, critical 10) to the missed glossary terms, sentences in the wrong register, tag errors and sentences that fail gender neutrality, each counted once. Formatting counts as met or missed and does not add to the total errors. The models that did not make the shortlist have automatic scores only: the shortlist. Gender neutrality: the Advanced requirements count the two best solutions of the language, with the gender-neutrality agent where they need it. The results of the other solutions are shown for information.

How we measure it: 11-01 · 11-02

Trade-offs in English to Vietnamese translation

Price vs quality

The two solutions that meet every Standard requirement in Vietnamese are one-step solutions on Anthropic LLMs. Translations from Anthropic Claude Fable 5 have 13.8 total errors per 1,000 words, as many as from Anthropic Claude Opus 4.8, and cost $33.56 per million characters against $16.82. They take 68 and 67 seconds per 1,000 words. Optimizing for quality marks both, as they tie on total errors, and optimizing for cost or latency selects the solution on Anthropic Claude Opus 4.8.

Constraints

A cost cap of $16.81 per million characters or less removes both solutions that meet every Standard requirement, and a cap between $16.82 and $33.56 keeps only the one on Anthropic Claude Opus 4.8. A time limit of 66 seconds per 1,000 words or less removes both. A real-time limit removes every solution that meets general translation quality. A limit of one step changes nothing, because both solutions are one-step solutions.

Agent effect

The Advanced requirements add gender neutrality. In Vietnamese, translations from both solutions that meet every Standard requirement have 100% of the sentences about people gender-neutral without the gender-neutrality agent. So meeting the Advanced requirements costs the same $16.82 per million characters and takes the same 67 seconds per 1,000 words as meeting the Standard ones.

English to Vietnamese translation quality levels

A solution meets general translation quality with no critical error, at most three major errors and at most 20 weighted errors per 1,000 words.

Optimize for

Basic requirements★★