The State of Translation Automation 2026 · Languages

English to Basque AI translation quality, cost and speed

What it takes to automate translation from English into Basque against 10 requirements in three levels: the solutions that meet them, what they cost and how fast they are, from the 2026 benchmark of 57 AI models and MT engines.

How good is AI translation from English to Basque?

Key findings on English to Basque translation

  1. 1Near missIn one step, the solution on OpenAI GPT-5.6 Sol meets every Standard requirement in Basque except general translation quality, with 21.8 weighted errors per 1,000 words and no major or critical error. It costs $7.92 per million characters and takes 87 seconds per 1,000 words.See the data →
  2. 2Cost driverThe shortlisted three-step solutions (translation + LQA + repair) in Basque cost $574 to $643 per million characters, against $2.01 to $30.30 for the one-step solutions. Meeting the Advanced requirements costs the same as meeting the Standard ones, with no gender-neutrality agent.See the data →

Find English to Basque 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 Basque, 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. Inconclusive: the three LQA judges agree on fewer than 90% of the sentences of the solution, so it has no general translation quality result (09-02). 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 Basque translation

Analysis

Two three-step solutions (translation + LQA + repair) meet every Standard requirement in Basque, and the one on OpenAI GPT-5.6 Sol has the fewest errors, the lowest cost and the shortest time. It has 11.9 total errors per 1,000 words against 13.5 for the one on Google Gemini 3.1 Pro Preview. It costs $574 against $577 per million characters and takes 209 against 273 seconds per 1,000 words. So optimizing for quality, cost or latency selects the same solution.

Constraints

Under a cost cap of at most $573 per million characters, a time limit of at most 208 seconds per 1,000 words or a limit of two steps, no solution meets even the Basic requirements in Basque. The three-step solution on Google Gemini 3.5 Flash is faster than the two that meet them, at 172 seconds per 1,000 words and $585 per million characters. It misses general translation quality on major errors alone, with 4 major errors and 18.1 weighted errors per 1,000 words.

Level step-up

The Advanced requirements add gender neutrality. Both three-step solutions (translation + LQA + repair) that meet every Standard requirement in Basque have 100% of the sentences about people gender-neutral without the gender-neutrality agent. So the solution on OpenAI GPT-5.6 Sol meets every Advanced requirement with the same 11.9 total errors per 1,000 words, $574 per million characters and 209 seconds per 1,000 words as under the Standard requirements.

English to Basque translation quality levels

Optimize for
Basic requirements☆☆

Tier 2: two or more solutions, none simple

Solutions that meet them
2 (0 one-step)
Simplest solution
three-step
Fewest errors

OpenAI GPT-5.6 Sol
three-step

Total errors per 1,000 words
11.9
Cost per million characters
$574
Seconds per 1,000 words
209
Lowest cost

OpenAI GPT-5.6 Sol
three-step

Total errors per 1,000 words
11.9
Cost per million characters
$574
Seconds per 1,000 words
209
Shortest time

OpenAI GPT-5.6 Sol
three-step

Total errors per 1,000 words
11.9
Cost per million characters
$574
Seconds per 1,000 words
209
Standard requirements☆☆

Tier 2: two or more solutions, none simple

Solutions that meet them
2 (0 one-step)
Simplest solution
three-step
Fewest errors

OpenAI GPT-5.6 Sol
three-step

Total errors per 1,000 words
11.9
Cost per million characters
$574
Seconds per 1,000 words
209
Lowest cost

OpenAI GPT-5.6 Sol
three-step

Total errors per 1,000 words
11.9
Cost per million characters
$574
Seconds per 1,000 words
209
Shortest time

OpenAI GPT-5.6 Sol
three-step

Total errors per 1,000 words
11.9
Cost per million characters
$574
Seconds per 1,000 words
209
Advanced requirements☆☆

Tier 2: two or more solutions, none simple

Solutions that meet them
2 (0 one-step)
Simplest solution
three-step
Fewest errors

OpenAI GPT-5.6 Sol
three-step

Total errors per 1,000 words
11.9
Cost per million characters
$574
Seconds per 1,000 words
209
Lowest cost

OpenAI GPT-5.6 Sol
three-step

Total errors per 1,000 words
11.9
Cost per million characters
$574
Seconds per 1,000 words
209
Shortest time

OpenAI GPT-5.6 Sol
three-step

Total errors per 1,000 words
11.9
Cost per million characters
$574
Seconds per 1,000 words
209

Optimize for selects one of the solutions that meet the level: the one with the fewest total errors, the lowest cost or the shortest time. Where no solution meets the level, the card shows the available solution with the fewest total errors and what it misses. Total errors count every requirement with countable errors.

Quality levelTierSolutionsSimplest solutionModelTotal errors per 1,000 wordsCost per million charactersSeconds per 1,000 words
BasicTier 2: two or more solutions, none simple☆☆three-stepOpenAI GPT-5.6 Sol11.9$574209
StandardTier 2: two or more solutions, none simple☆☆three-stepOpenAI GPT-5.6 Sol11.9$574209
AdvancedTier 2: two or more solutions, none simple☆☆three-stepOpenAI GPT-5.6 Sol11.9$574209

One solution per level: the simplest that meets the level, the cheapest of them where several are equally simple. ★ a one-step solution, ☆ a solution with more steps or the gender-neutrality agent.

Level step-up

In Basque two three-step solutions (translation + LQA + repair), on OpenAI GPT-5.6 Sol and Google Gemini 3.1 Pro Preview, meet general translation quality. Both also meet tone of voice, tag handling and formatting, and gender neutrality without the gender-neutrality agent. So neither the Standard nor the Advanced requirements remove a solution, and every level takes three steps. At each level, optimizing for quality, cost or latency selects the solution on OpenAI GPT-5.6 Sol, with 11.9 total errors per 1,000 words.

How we measure it: 11-01 · 11-02 · 08-09

English to Basque translation cost against errors

Chart data
Cost and weighted errors of the one-step solutions in Basque
ModelUS dollars per million charactersWeighted errors per 1,000 wordsGroup
z.ai GLM-52.0196.9Misses a Standard requirement
OpenAI GPT-4.13.1187.3Misses a Standard requirement
Google Gemini 3.5 Flash3.6439.2Misses a Standard requirement
Google Gemini 3.1 Pro Preview4.8726.4Misses a Standard requirement
OpenAI GPT-5.6 Sol7.9221.8Misses a Standard requirement
OpenAI GPT-5.511.4734.6Misses a Standard requirement
Anthropic Claude Opus 4.815.251.7Misses a Standard requirement
Google Translation LLM2176.1Misses a Standard requirement
DeepL Next Gen27.5127.2Misses a Standard requirement
Anthropic Claude Fable 530.335.9Misses a Standard requirement
Price vs quality

Up to $7.92 per million characters, a dearer one-step solution in Basque has fewer weighted errors. The five there with a conclusive Intento LQA result are on LLMs, from the one on z.ai GLM-5, at $2.01 per million characters and 96.9 weighted errors per 1,000 words, to the one on OpenAI GPT-5.6 Sol, at 21.8 weighted errors per 1,000 words. The five such solutions that cost more, $11.47 to $30.30 per million characters, have 34.6 to 127.2 weighted errors per 1,000 words. Two of them are on LLM-based MT engines.

How we measure it: 11-01 · 10-10

English to Basque translation requirements

Chart data
Errors per 1,000 words of the one-step solutions in Basque, median, by requirement
RequirementMedian errors per 1,000 words
General translation quality45.5
Tone of voice0
Tag handling0
Gender neutrality0

The requirements with countable errors. Every solution with its result on each requirement: the explorer.

Bottleneck

The one-step solution closest to the bar of general translation quality is on OpenAI GPT-5.6 Sol, with 21.8 weighted errors per 1,000 words and no major or critical error. Two-step solutions (translation + post-edit) on four models have 25.0 to 83.4 weighted errors per 1,000 words. Three-step solutions (translation + LQA + repair) on four models stay under the bar on weighted errors, but those on OpenAI GPT-5.5 and Google Gemini 3.5 Flash have 5 and 4 major errors. Every three-step solution meets tag handling and formatting.

How we measure it: 09-09 · 09-10 · 09-11 · 09-12 · 09-18

AI models and MT engines for English to Basque translation

Chart data
Weighted errors per 1,000 words of the shortlisted one-step solutions in Basque
ModelWeighted errors per 1,000 words of the shortlisted one-step solutions in BasqueClass
DeepL Next Gen127.2LLM-based MT engines
z.ai GLM-596.9LLMs
OpenAI GPT-4.187.3LLMs
Google Translation LLM76.1LLM-based MT engines
Anthropic Claude Opus 4.851.7LLMs
Google Gemini 3.5 Flash39.2LLMs
Anthropic Claude Fable 535.9LLMs
OpenAI GPT-5.534.6LLMs
Google Gemini 3.1 Pro Preview26.4LLMs
OpenAI GPT-5.6 Sol21.8LLMs
Model types

The shortlist for Basque holds nine LLMs and three LLM-based MT engines. The four open-weight LLMs and five other MT engines we got translations from are outside it. For one LLM, Anthropic Claude Sonnet 5, we have no conclusive Intento LQA result. Our language-support criteria cover the other eight. In one step, translations from six of them have 21.8 to 51.7 weighted errors per 1,000 words and meet the criteria. Those from OpenAI GPT-4.1 and z.ai GLM-5 have 87.3 and 96.9 weighted errors per 1,000 words, above the 60 of the criteria.

How we measure it: 00-04 · 08-15 · 23-01

How we shortlisted English to Basque translation solutions

Chart data
Ranks of the models on the two automatic metrics, Basque
ModelCOMET-KiwiRank on COMET-KiwiMetricXRank on MetricXShortlistedShortlist place
DeepSeek V3.20.779112.4313NoNot shortlisted
Anthropic Claude Sonnet 4.60.779122.4011NoNot shortlisted
xAI Grok 4.20 (reasoning)0.770152.5714NoNot shortlisted
Microsoft Translator0.766162.9319NoNot shortlisted
MoonshotAI Kimi K2.50.763172.6015NoNot shortlisted
Mistral Large 30.763183.0920NoNot shortlisted
Elia Machine Translation System0.762192.7017NoNot shortlisted
Mistral Medium 3.10.758202.7318NoNot shortlisted
Google Cloud Advanced Translation API0.753213.1722NoNot shortlisted
OpenAI gpt-oss-120b0.740223.1621NoNot shortlisted
Swiss AI Apertus-8B-25090.739233.1823NoNot shortlisted
Yandex Cloud Translate v20.723243.6925NoNot shortlisted
Anthropic Claude Haiku 4.50.722253.9228NoNot shortlisted
Google Gemma 40.721264.2129NoNot shortlisted
MiniMax M2.50.718273.5524NoNot shortlisted
Alibaba Qwen3-235B-A22B0.707283.8227NoNot shortlisted
Cohere Command A Translate0.703293.7226NoNot shortlisted
Cohere Tiny Aya0.643305.6330NoNot shortlisted
AI21 Jamba Large 1.70.605316.1031NoNot shortlisted
Alibaba Machine Translation API0.545328.3132NoNot shortlisted
Google Gemini 3.1 Pro Preview0.79912.031YesTop 8 by both metrics
OpenAI GPT-5.50.79522.135YesTop 8 by both metrics
OpenAI GPT-5.6 Sol0.79532.042YesTop 8 by both metrics
Anthropic Claude Fable 50.79042.073YesTop 8 by both metrics
Anthropic Claude Sonnet 50.78952.3610YesTop 8 by COMET-Kiwi
Anthropic Claude Opus 4.80.78662.287YesTop 8 by both metrics
z.ai GLM-50.78372.349YesTop 8 by COMET-Kiwi
OpenAI GPT-4.10.78282.328YesTop 8 by both metrics
DeepL Next Gen0.78292.114YesTop 8 by MetricX
Google Gemini 3.5 Flash0.779102.276YesTop 8 by MetricX
Google Translation LLM0.775132.4112YesReal-time place
Translated Lara 20.775142.6916YesReal-time place
ModelSolution complexityCOMET-Kiwi rankCOMET-KiwiMetricX rankMetricXShortlist
Google Gemini 3.1 Pro PreviewAdjusted LLM10.79912.03Top 8 by both metrics
OpenAI GPT-5.5Adjusted LLM20.79552.13Top 8 by both metrics
OpenAI GPT-5.6 SolAdjusted LLM30.79522.04Top 8 by both metrics
Anthropic Claude Fable 5Adjusted LLM40.79032.07Top 8 by both metrics
Anthropic Claude Sonnet 5Adjusted LLM50.789102.36Top 8 by COMET-Kiwi
Anthropic Claude Opus 4.8Adjusted LLM60.78672.28Top 8 by both metrics
z.ai GLM-5Adjusted LLM70.78392.34Top 8 by COMET-Kiwi
OpenAI GPT-4.1Adjusted LLM80.78282.32Top 8 by both metrics
DeepL Next GenOff-the-shelf NMT90.78242.11Top 8 by MetricX
Google Gemini 3.5 FlashAdjusted LLM100.77962.27Top 8 by MetricX
DeepSeek V3.2Adjusted LLM110.779132.43Not shortlisted
Anthropic Claude Sonnet 4.6Adjusted LLM120.779112.40Not shortlisted
Google Translation LLMAdjusted NMT130.775122.41Real-time place
Translated Lara 2Adjusted NMT140.775162.69Real-time place
xAI Grok 4.20 (reasoning)Adjusted LLM150.770142.57Not shortlisted
Microsoft TranslatorOff-the-shelf NMT160.766192.93Not shortlisted
MoonshotAI Kimi K2.5Adjusted LLM170.763152.60Not shortlisted
Mistral Large 3Adjusted LLM180.763203.09Not shortlisted
Elia Machine Translation SystemOff-the-shelf NMT190.762172.70Not shortlisted
Mistral Medium 3.1Adjusted LLM200.758182.73Not shortlisted
Google Cloud Advanced Translation APIOff-the-shelf NMT210.753223.17Not shortlisted
OpenAI gpt-oss-120bAdjusted LLM220.740213.16Not shortlisted
Swiss AI Apertus-8B-2509Off-the-shelf LLM230.739233.18Not shortlisted
Yandex Cloud Translate v2Off-the-shelf NMT240.723253.69Not shortlisted
Anthropic Claude Haiku 4.5Adjusted LLM250.722283.92Not shortlisted
Google Gemma 4Adjusted LLM260.721294.21Not shortlisted
MiniMax M2.5Off-the-shelf LLM270.718243.55Not shortlisted
Alibaba Qwen3-235B-A22BAdjusted LLM280.707273.82Not shortlisted
Cohere Command A TranslateAdjusted LLM290.703263.72Not shortlisted
Cohere Tiny AyaAdjusted LLM300.643305.63Not shortlisted
AI21 Jamba Large 1.7Off-the-shelf LLM310.605316.10Not shortlisted
Alibaba Machine Translation APIOff-the-shelf NMT320.545328.31Not shortlisted
OpenAI GPT-5.6 LunaAdjusted LLM—0.794—2.24Same model family as OpenAI GPT-5.6 Sol
OpenAI GPT-5.6 TerraAdjusted LLM—0.790—2.16Same model family as OpenAI GPT-5.6 Sol
xAI Grok 4.20 (non-reasoning)Adjusted LLM—0.765—2.56Same model family as xAI Grok 4.20 (reasoning)

Every model we got a translation from, as the shortlist compared it: off the shelf, without context in the request, or adjusted, with it. A model that did not make the shortlist is shown adjusted, unless off the shelf it scores higher by 0.03 or more on COMET-Kiwi. Ranks among 32 models, with each model family counted once, and the top 8 of each metric in bold. Higher is better on COMET-Kiwi, lower on MetricX. The scores rank models within this language and are not a requirement result.

Metrics vs LQA

Both metrics rank Google Gemini 3.1 Pro Preview first, yet by Intento LQA the one-step solution on OpenAI GPT-5.6 Sol has fewer weighted errors, 21.8 against 26.4 per 1,000 words. MetricX ranks DeepL Next Gen fourth, and the solution on DeepL Next Gen has the most weighted errors of those with a conclusive Intento LQA result, 127.2 per 1,000 words. Anthropic Claude Sonnet 5 and z.ai GLM-5 made the list through COMET-Kiwi alone. Nearest the cut are DeepSeek V3.2, 11th on COMET-Kiwi, and Anthropic Claude Sonnet 4.6, 11th on MetricX.

How we measure it: 00-08 · 00-09

English to Basque translation cost

Quality levelCheapest solution that meets every requirement of the levelCost per million characters
BasicOpenAI GPT-5.6 Sol, three-step$574
StandardOpenAI GPT-5.6 Sol, three-step$574
AdvancedOpenAI GPT-5.6 Sol, three-step$574
Chart data
Cost of the shortlisted one-step solutions in Basque
ModelUS dollars per million charactersClass
z.ai GLM-5$2.01LLMs
OpenAI GPT-4.1$3.11LLMs
Google Gemini 3.5 Flash$3.64LLMs
Google Gemini 3.1 Pro Preview$4.87LLMs
Anthropic Claude Sonnet 5$6.05LLMs
OpenAI GPT-5.6 Sol$7.92LLMs
OpenAI GPT-5.5$11.47LLMs
Anthropic Claude Opus 4.8$15.2LLMs
Google Translation LLM$21LLM-based MT engines
Translated Lara 2$24.99LLM-based MT engines
DeepL Next Gen$27.5LLM-based MT engines
Anthropic Claude Fable 5$30.3LLMs
Chart data
Tokens per character of the translation into Basque, by model
ModelTokens per characterClass
Anthropic Claude Fable 50.5LLMs
Anthropic Claude Sonnet 50.5LLMs
Anthropic Claude Opus 4.80.498LLMs
Mistral Medium 3.10.415LLMs
Mistral Large 30.41LLMs
Anthropic Claude Sonnet 4.60.4LLMs
AI21 Jamba Large 1.70.387LLMs
Anthropic Claude Haiku 4.50.379LLMs
Alibaba Qwen3-235B-A22B0.363Open-weight LLMs
MoonshotAI Kimi K2.50.357LLMs
Cohere Command A Translate0.356LLMs
z.ai GLM-50.353LLMs
DeepSeek V3.20.344LLMs
xAI Grok 4.20 (non-reasoning)0.338LLMs
xAI Grok 4.20 (reasoning)0.337LLMs
Google Gemini 3.1 Pro Preview0.335LLMs
Google Gemini 3.5 Flash0.334LLMs
Google Gemma 40.332Open-weight LLMs
OpenAI GPT-4.10.316LLMs
OpenAI GPT-5.6 Terra0.316LLMs
OpenAI GPT-5.50.315LLMs
OpenAI GPT-5.6 Sol0.315LLMs
OpenAI GPT-5.6 Luna0.314LLMs
MiniMax M2.50.307LLMs
Cohere Tiny Aya0.304LLMs
Cost driver

On OpenAI GPT-5.6 Sol, the one-step solution costs $7.92 per million characters, the two-step one (translation + post-edit) $20.04 and the three-step one (translation + LQA + repair) $574. The tokenizer of Anthropic Claude Sonnet 5 produces 0.5 tokens per character of the translation, against 0.315 for that of OpenAI GPT-5.6 Sol, and yet the one-step solution on Anthropic Claude Sonnet 5 costs less, $6.05 per million characters. Meeting the Advanced requirements costs $574 per million characters, as meeting the Basic ones does.

How we measure it: 10-01 · 10-03 · 05-02

English to Basque translation speed

Quality levelFastest solution that meets every requirement of the levelSeconds per 1,000 words
BasicOpenAI GPT-5.6 Sol, three-step209
StandardOpenAI GPT-5.6 Sol, three-step209
AdvancedOpenAI GPT-5.6 Sol, three-step209
Chart data
Time to translate 1,000 words into Basque, by model
ModelSeconds per 1,000 wordsClass
Google Cloud Advanced Translation API0.1MT engines
Microsoft Translator0.2MT engines
Google Translation LLM0.5LLM-based MT engines
DeepL Next Gen0.8LLM-based MT engines
Translated Lara 21.6LLM-based MT engines
OpenAI gpt-oss-120b2.2Open-weight LLMs
Elia Machine Translation System3.6MT engines
Yandex Cloud Translate v23.6MT engines
Cohere Tiny Aya16LLMs
OpenAI GPT-5.6 Luna17LLMs
xAI Grok 4.20 (non-reasoning)23LLMs
Alibaba Machine Translation API28MT engines
OpenAI GPT-4.134LLMs
Mistral Medium 3.138LLMs
Swiss AI Apertus-8B-250940Open-weight LLMs
Anthropic Claude Haiku 4.545LLMs
OpenAI GPT-5.6 Terra47LLMs
MiniMax M2.551LLMs
AI21 Jamba Large 1.758LLMs
Google Gemini 3.5 Flash60LLMs
Mistral Large 360LLMs
Cohere Command A Translate62LLMs
xAI Grok 4.20 (reasoning)65LLMs
DeepSeek V3.268LLMs
Anthropic Claude Sonnet 580LLMs
Google Gemini 3.1 Pro Preview86LLMs
Anthropic Claude Sonnet 4.686LLMs
OpenAI GPT-5.6 Sol87LLMs
Anthropic Claude Fable 588LLMs
OpenAI GPT-5.589LLMs
Anthropic Claude Opus 4.8105LLMs
Alibaba Qwen3-235B-A22B117Open-weight LLMs
Google Gemma 4167Open-weight LLMs
MoonshotAI Kimi K2.5182LLMs
z.ai GLM-5265LLMs

Real-time models are those the shortlist counts as real-time, under 2 seconds per text across the languages we timed. The chart shows the time of each model into Basque.

Real-time

The real-time models for Basque are three LLM-based MT engines, two other MT engines and the open-weight OpenAI gpt-oss-120b. The three LLM-based MT engines are on the shortlist. Translations from DeepL Next Gen and Google Translation LLM have 94.1% and 95.1% of the tags right. The one-step LLM solutions on the shortlist take 34 to 265 seconds per 1,000 words. At every quality level, the fastest solution that meets it is the three-step solution (translation + LQA + repair) on OpenAI GPT-5.6 Sol, at 209 seconds per 1,000 words.

How we measure it: 12-01 · 12-02 · 12-09

Tone of voice and gender-neutral English to Basque translation

Tone of voice
Formal register, with zu (zuka)
Gender-neutrality strategy
No grammatical gender for persons in formal register — neutral by default; only avoid gendered terms
Default gender
None where the source leaves the gender open
The two best solutionsSolutionSentences about people that are gender-neutralMeets every Advanced requirementCost per million charactersSeconds per 1,000 words
OpenAI GPT-5.6 Solthree-step100%✓$574209
Google Gemini 3.1 Pro Previewthree-step100%✓$577273
Analysis

For Basque we check the formal register, with the form of address zu (zuka), and gender neutrality: no gender absent from the English source and no default gender. Basque has no grammatical gender for persons in the formal register, so formal translations are gender-neutral by default, gendered terms aside. Every shortlisted solution meets tone of voice. Both three-step solutions (translation + LQA + repair) that meet every Advanced requirement have 100% of the sentences about people gender-neutral without the gender-neutrality agent.

How we measure it: 02-05 · 02-06 · 08-11 · 09-18

How confident are we in measuring English to Basque translation quality?

Confidence

For the 12 shortlisted solutions in Basque, the median share of sentences on which the three LQA judges agree is 91.2%. The quality-estimation pair of automatic metrics has an agreement of 0.67 against a floor of 0.53, and the similarity pair 0.59 against a floor of 0.46. The low ends of their ranges, 0.66 and 0.58, also stay above the floors. So the ranking of the shortlist and the Intento LQA error counts on this page carry weight in Basque.

How we measure it: 00-07 · 07-05 · 09-02

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