The State of Translation Automation 2026 · Languages

English to Swahili AI translation quality, cost and speed

What it takes to automate translation from English into Swahili 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 Swahili?

Key findings on English to Swahili translation

  1. 1BottleneckOf the one-step solutions in Swahili with a conclusive Intento LQA result, the one on Anthropic Claude Fable 5 comes closest to the bar of general translation quality, with 36.3 weighted errors per 1,000 words, and the three-step solution (translation + LQA + repair) on the same model has 9.6.See the data →
  2. 2Cost driverThe solution on OpenAI GPT-5.6 Luna costs $0.43 per million characters in one step, $1.02 in two steps (translation + post-edit) and $543 in three steps (translation + LQA + repair). Only the three-step one meets general translation quality in Swahili.See the data →
  3. 3Near missThe three-step solution (translation + LQA + repair) on OpenAI GPT-4.1, at $582 per million characters, misses general translation quality in Swahili by a small margin. The translations have 22.7 weighted errors per 1,000 words, just over the bar, and four major errors, more than the bar allows.See the data →

Find English to Swahili 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 Swahili, 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 11 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 Swahili translation

Trade-off

Three three-step solutions (translation + LQA + repair) meet every Standard requirement in Swahili, and none leads on errors, cost and time at once. The one on Anthropic Claude Fable 5 has 9.6 total errors per 1,000 words and takes 216 seconds per 1,000 words. The one on OpenAI GPT-5.6 Luna has 13.2 total errors per 1,000 words and takes 119 seconds per 1,000 words. Optimizing for quality selects Anthropic Claude Fable 5, and optimizing for cost or latency OpenAI GPT-5.6 Luna.

Agent effect

The Advanced requirements add gender neutrality, and in Swahili the gender-neutrality agent is not needed. Translations from the three-step solutions on Anthropic Claude Fable 5 and OpenAI GPT-5.6 Luna, the two best solutions, have 100% of the sentences about people gender-neutral without it. So they meet every Advanced requirement at the same $617 and $543 per million characters and the same 216 and 119 seconds per 1,000 words.

English to Swahili translation quality levels

Optimize for
Basic requirements☆☆☆

Tier 2: two or more solutions, none simple

Solutions that meet them
3 (0 one-step)
Simplest solution
three-step
Fewest errors

Anthropic Claude Fable 5
three-step

Total errors per 1,000 words
9.6
Cost per million characters
$617
Seconds per 1,000 words
216
Lowest cost

OpenAI GPT-5.6 Luna
three-step

Total errors per 1,000 words
13.2
Cost per million characters
$543
Seconds per 1,000 words
119
Shortest time

OpenAI GPT-5.6 Luna
three-step

Total errors per 1,000 words
13.2
Cost per million characters
$543
Seconds per 1,000 words
119
Standard requirements☆☆☆

Tier 2: two or more solutions, none simple

Solutions that meet them
3 (0 one-step)
Simplest solution
three-step
Fewest errors

Anthropic Claude Fable 5
three-step

Total errors per 1,000 words
9.6
Cost per million characters
$617
Seconds per 1,000 words
216
Lowest cost

OpenAI GPT-5.6 Luna
three-step

Total errors per 1,000 words
13.2
Cost per million characters
$543
Seconds per 1,000 words
119
Shortest time

OpenAI GPT-5.6 Luna
three-step

Total errors per 1,000 words
13.2
Cost per million characters
$543
Seconds per 1,000 words
119
Advanced requirements☆☆

Tier 2: two or more solutions, none simple

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

Anthropic Claude Fable 5
three-step

Total errors per 1,000 words
9.6
Cost per million characters
$617
Seconds per 1,000 words
216
Lowest cost

OpenAI GPT-5.6 Luna
three-step

Total errors per 1,000 words
13.2
Cost per million characters
$543
Seconds per 1,000 words
119
Shortest time

OpenAI GPT-5.6 Luna
three-step

Total errors per 1,000 words
13.2
Cost per million characters
$543
Seconds per 1,000 words
119

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 Luna13.2$543119
StandardTier 2: two or more solutions, none simple☆☆☆three-stepOpenAI GPT-5.6 Luna13.2$543119
AdvancedTier 2: two or more solutions, none simple☆☆three-stepOpenAI GPT-5.6 Luna13.2$543119

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

The Standard requirements keep all three three-step solutions (translation + LQA + repair) that meet every Basic requirement in Swahili. Translations from all three have 100% of the sentences in the formal register and 100% of the tags right. The Advanced requirements keep the two best solutions, on Anthropic Claude Fable 5 and OpenAI GPT-5.6 Luna, the only ones they count for gender neutrality. For all three levels, optimizing for quality selects Anthropic Claude Fable 5, and optimizing for cost or latency OpenAI GPT-5.6 Luna.

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

English to Swahili translation cost against errors

Chart data
Cost and weighted errors of the one-step solutions in Swahili
ModelUS dollars per million charactersWeighted errors per 1,000 wordsGroup
Google Gemma 40.1454.7Misses a Standard requirement
OpenAI GPT-5.6 Luna0.4342.2Misses a Standard requirement
DeepSeek V3.20.9951.7Misses a Standard requirement
OpenAI GPT-4.12.9553.4Misses a Standard requirement
Google Gemini 3.5 Flash3.5749.8Misses a Standard requirement
Google Gemini 3.1 Pro Preview4.7545.8Misses a Standard requirement
Google Translation LLM20.987.3Misses a Standard requirement
Anthropic Claude Fable 531.2636.3Misses a Standard requirement
Price vs quality

Among the one-step solutions in Swahili with a conclusive Intento LQA result, the dearest, on Anthropic Claude Fable 5 at $31.26 per million characters, has the fewest weighted errors, 36.3 per 1,000 words. The one on OpenAI GPT-5.6 Luna costs $0.43 per million characters and has 42.2 weighted errors per 1,000 words, fewer than those on Google Gemini 3.1 Pro Preview and Google Gemini 3.5 Flash at $4.75 and $3.57. Google Translation LLM costs $20.90 per million characters and has the most, 87.3 weighted errors per 1,000 words.

How we measure it: 11-01 · 10-10

English to Swahili translation requirements

Chart data
Errors per 1,000 words of the one-step solutions in Swahili, median, by requirement
RequirementMedian errors per 1,000 words
General translation quality50.8
Tone of voice0.2
Tag handling0
Gender neutrality0

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

Bottleneck

Translations from OpenAI GPT-5.6 Luna have 42.2 weighted errors per 1,000 words in one step and 38.6 in two steps (translation + post-edit), over the bar of general translation quality in Swahili. In three steps (translation + LQA + repair), the solutions on Anthropic Claude Fable 5, OpenAI GPT-5.6 Luna and Google Gemini 3.1 Pro Preview have 9.6 to 13.8 weighted errors per 1,000 words, and those on OpenAI GPT-4.1 and Google Gemini 3.5 Flash 22.7 and 26.7. Translations from all five have 100% of the tags right.

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

AI models and MT engines for English to Swahili translation

Chart data
Weighted errors per 1,000 words of the shortlisted one-step solutions in Swahili
ModelWeighted errors per 1,000 words of the shortlisted one-step solutions in SwahiliClass
Google Translation LLM87.3LLM-based MT engines
Google Gemma 454.7Open-weight LLMs
OpenAI GPT-4.153.4LLMs
DeepSeek V3.251.7LLMs
Google Gemini 3.5 Flash49.8LLMs
Google Gemini 3.1 Pro Preview45.8LLMs
OpenAI GPT-5.6 Luna42.2LLMs
Anthropic Claude Fable 536.3LLMs
Model types

The seven shortlisted LLMs with a conclusive Intento LQA result support Swahili by our criteria, the open-weight Google Gemma 4 among them. Translations from these LLMs in one step have 36.3 to 54.7 weighted errors per 1,000 words, the most from Google Gemma 4, 1.51 times as many as from Anthropic Claude Fable 5. Translations from Google Translation LLM, the one LLM-based MT engine with such a result, have 87.3 weighted errors per 1,000 words and 8 critical errors. None of the MT engines that are not LLM-based made the shortlist.

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

How we shortlisted English to Swahili translation solutions

Chart data
Ranks of the models on the two automatic metrics, Swahili
ModelCOMET-KiwiRank on COMET-KiwiMetricXRank on MetricXShortlistedShortlist place
Anthropic Claude Opus 4.80.73691.8912NoNot shortlisted
Anthropic Claude Sonnet 50.736101.8911NoNot shortlisted
xAI Grok 4.20 (reasoning)0.734112.2121NoNot shortlisted
OpenAI GPT-5.50.733131.9714NoNot shortlisted
z.ai GLM-50.730161.9213NoNot shortlisted
ALL-Lab0.728171.8810NoNot shortlisted
Mistral Large 30.726182.1719NoNot shortlisted
OpenAI gpt-oss-120b0.718192.0515NoNot shortlisted
Microsoft Translator0.716202.1920NoNot shortlisted
MoonshotAI Kimi K2.50.710212.1518NoNot shortlisted
ModernMT Enterprise Edition0.710222.2522NoNot shortlisted
Google Cloud Advanced Translation API0.699232.9427NoNot shortlisted
Anthropic Claude Haiku 4.50.697242.6824NoNot shortlisted
Swiss AI Apertus-8B-25090.696252.9828NoNot shortlisted
Mistral Medium 3.10.691262.6423NoNot shortlisted
MiniMax M2.50.685272.7525NoNot shortlisted
Yandex Cloud Translate v20.685282.9126NoNot shortlisted
Amazon Translate0.668293.4329NoNot shortlisted
Cohere Tiny Aya0.656304.3232NoNot shortlisted
Alibaba Machine Translation API0.645313.8130NoNot shortlisted
SYSTRAN PNMT API0.641324.0131NoNot shortlisted
Alibaba Qwen3-235B-A22B0.620334.7833NoNot shortlisted
AI21 Jamba Large 1.70.559346.8734NoNot shortlisted
Cohere Command A Translate0.519358.1035NoNot shortlisted
Anthropic Claude Sonnet 4.60.74711.754YesTop 8 by both metrics
Google Gemini 3.1 Pro Preview0.74621.672YesTop 8 by both metrics
Google Gemini 3.5 Flash0.74431.601YesTop 8 by both metrics
OpenAI GPT-5.6 Luna0.74041.693YesTop 8 by both metrics
OpenAI GPT-4.10.73951.787YesTop 8 by both metrics
Anthropic Claude Fable 50.73761.808YesTop 8 by both metrics
Google Gemma 40.73771.775YesTop 8 by both metrics
DeepL Next Gen0.73681.819YesTop 8 by COMET-Kiwi
DeepSeek V3.20.733121.776YesTop 8 by MetricX
Translated Lara 20.733142.0816YesReal-time place
Google Translation LLM0.733152.1017YesReal-time place
ModelSolution complexityCOMET-Kiwi rankCOMET-KiwiMetricX rankMetricXShortlist
Anthropic Claude Sonnet 4.6Adjusted LLM10.74741.75Top 8 by both metrics
Google Gemini 3.1 Pro PreviewAdjusted LLM20.74621.67Top 8 by both metrics
Google Gemini 3.5 FlashAdjusted LLM30.74411.60Top 8 by both metrics
OpenAI GPT-5.6 LunaAdjusted LLM40.74031.69Top 8 by both metrics
OpenAI GPT-4.1Adjusted LLM50.73971.78Top 8 by both metrics
Anthropic Claude Fable 5Adjusted LLM60.73781.80Top 8 by both metrics
Google Gemma 4Adjusted LLM70.73751.77Top 8 by both metrics
DeepL Next GenOff-the-shelf NMT80.73691.81Top 8 by COMET-Kiwi
Anthropic Claude Opus 4.8Adjusted LLM90.736121.89Not shortlisted
Anthropic Claude Sonnet 5Adjusted LLM100.736111.89Not shortlisted
xAI Grok 4.20 (reasoning)Adjusted LLM110.734212.21Not shortlisted
DeepSeek V3.2Adjusted LLM120.73361.77Top 8 by MetricX
OpenAI GPT-5.5Adjusted LLM130.733141.97Not shortlisted
Translated Lara 2Adjusted NMT140.733162.08Real-time place
Google Translation LLMAdjusted NMT150.733172.10Real-time place
z.ai GLM-5Adjusted LLM160.730131.92Not shortlisted
ALL-LabOff-the-shelf NMT170.728101.88Not shortlisted
Mistral Large 3Adjusted LLM180.726192.17Not shortlisted
OpenAI gpt-oss-120bAdjusted LLM190.718152.05Not shortlisted
Microsoft TranslatorOff-the-shelf NMT200.716202.19Not shortlisted
MoonshotAI Kimi K2.5Adjusted LLM210.710182.15Not shortlisted
ModernMT Enterprise EditionOff-the-shelf NMT220.710222.25Not shortlisted
Google Cloud Advanced Translation APIOff-the-shelf NMT230.699272.94Not shortlisted
Anthropic Claude Haiku 4.5Adjusted LLM240.697242.68Not shortlisted
Swiss AI Apertus-8B-2509Off-the-shelf LLM250.696282.98Not shortlisted
Mistral Medium 3.1Adjusted LLM260.691232.64Not shortlisted
MiniMax M2.5Adjusted LLM270.685252.75Not shortlisted
Yandex Cloud Translate v2Off-the-shelf NMT280.685262.91Not shortlisted
Amazon TranslateOff-the-shelf NMT290.668293.43Not shortlisted
Cohere Tiny AyaOff-the-shelf LLM300.656324.32Not shortlisted
Alibaba Machine Translation APIOff-the-shelf NMT310.645303.81Not shortlisted
SYSTRAN PNMT APIOff-the-shelf NMT320.641314.01Not shortlisted
Alibaba Qwen3-235B-A22BAdjusted LLM330.620334.78Not shortlisted
AI21 Jamba Large 1.7Adjusted LLM340.559346.87Not shortlisted
Cohere Command A TranslateAdjusted LLM350.519358.10Not shortlisted
OpenAI GPT-5.6 SolAdjusted LLM—0.736—1.63Same model family as OpenAI GPT-5.6 Luna
OpenAI GPT-5.6 TerraAdjusted LLM—0.736—1.84Same model family as OpenAI GPT-5.6 Luna
xAI Grok 4.20 (non-reasoning)Adjusted LLM—0.729—1.99Same 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 35 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

MetricX ranks Google Gemini 3.5 Flash first in Swahili, and by Intento LQA the one-step solution on that model has 49.8 weighted errors per 1,000 words and one critical error. Of the one-step solutions with a conclusive Intento LQA result, the one on Anthropic Claude Fable 5, sixth on COMET-Kiwi, has the fewest weighted errors, 36.3 per 1,000 words. DeepSeek V3.2 is on the list through MetricX alone, sixth there and 12th on COMET-Kiwi. Nearest the cut are Anthropic Claude Opus 4.8, ninth on COMET-Kiwi, and ALL-Lab, 10th on MetricX.

How we measure it: 00-08 · 00-09

English to Swahili translation cost

Quality levelCheapest solution that meets every requirement of the levelCost per million characters
BasicOpenAI GPT-5.6 Luna, three-step$543
StandardOpenAI GPT-5.6 Luna, three-step$543
AdvancedOpenAI GPT-5.6 Luna, three-step$543
Chart data
Cost of the shortlisted one-step solutions in Swahili
ModelUS dollars per million charactersClass
Google Gemma 4$0.14Open-weight LLMs
OpenAI GPT-5.6 Luna$0.43LLMs
DeepSeek V3.2$0.99LLMs
OpenAI GPT-4.1$2.95LLMs
Google Gemini 3.5 Flash$3.57LLMs
Google Gemini 3.1 Pro Preview$4.75LLMs
Anthropic Claude Sonnet 4.6$7.11LLMs
Google Translation LLM$20.9LLM-based MT engines
Translated Lara 2$24.99LLM-based MT engines
DeepL Next Gen$27.5LLM-based MT engines
Anthropic Claude Fable 5$31.26LLMs
Chart data
Tokens per character of the translation into Swahili, by model
ModelTokens per characterClass
Anthropic Claude Opus 4.80.527LLMs
Anthropic Claude Sonnet 50.527LLMs
Anthropic Claude Fable 50.526LLMs
Mistral Large 30.427LLMs
Mistral Medium 3.10.427LLMs
Anthropic Claude Sonnet 4.60.404LLMs
Anthropic Claude Haiku 4.50.401LLMs
Alibaba Qwen3-235B-A22B0.385Open-weight LLMs
DeepSeek V3.20.377LLMs
z.ai GLM-50.374LLMs
AI21 Jamba Large 1.70.373LLMs
Cohere Command A Translate0.368LLMs
MoonshotAI Kimi K2.50.365LLMs
xAI Grok 4.20 (non-reasoning)0.349LLMs
xAI Grok 4.20 (reasoning)0.348LLMs
Google Gemini 3.1 Pro Preview0.334LLMs
Google Gemini 3.5 Flash0.334LLMs
Google Gemma 40.332Open-weight LLMs
MiniMax M2.50.33LLMs
OpenAI GPT-5.6 Terra0.304LLMs
OpenAI GPT-5.50.303LLMs
OpenAI GPT-4.10.302LLMs
OpenAI GPT-5.6 Luna0.302LLMs
OpenAI GPT-5.6 Sol0.301LLMs
Cohere Tiny Aya0.293LLMs

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

English to Swahili translation speed

Quality levelFastest solution that meets every requirement of the levelSeconds per 1,000 words
BasicOpenAI GPT-5.6 Luna, three-step119
StandardOpenAI GPT-5.6 Luna, three-step119
AdvancedOpenAI GPT-5.6 Luna, three-step119
Chart data
Time to translate 1,000 words into Swahili, by model
ModelSeconds per 1,000 wordsClass
Google Cloud Advanced Translation API0.1MT engines
Microsoft Translator0.2MT engines
ModernMT Enterprise Edition0.3MT engines
Google Translation LLM0.6LLM-based MT engines
DeepL Next Gen0.7LLM-based MT engines
SYSTRAN PNMT API0.9MT engines
Amazon Translate1.2MT engines
Translated Lara 21.5LLM-based MT engines
OpenAI gpt-oss-120b2.1Open-weight LLMs
Yandex Cloud Translate v23.9MT engines
OpenAI GPT-5.6 Luna15LLMs
Google Gemini 3.5 Flash17LLMs
Cohere Tiny Aya20LLMs
OpenAI GPT-4.122LLMs
xAI Grok 4.20 (non-reasoning)23LLMs
Alibaba Machine Translation API27MT engines
ALL-Lab32MT engines
OpenAI GPT-5.6 Terra37LLMs
Anthropic Claude Haiku 4.545LLMs
Swiss AI Apertus-8B-250946Open-weight LLMs
Mistral Medium 3.147LLMs
DeepSeek V3.258LLMs
Cohere Command A Translate62LLMs
MiniMax M2.564LLMs
Anthropic Claude Sonnet 567LLMs
xAI Grok 4.20 (reasoning)67LLMs
Anthropic Claude Fable 568LLMs
Mistral Large 370LLMs
AI21 Jamba Large 1.774LLMs
OpenAI GPT-5.576LLMs
Anthropic Claude Opus 4.884LLMs
Google Gemini 3.1 Pro Preview85LLMs
OpenAI GPT-5.6 Sol85LLMs
Anthropic Claude Sonnet 4.686LLMs
Alibaba Qwen3-235B-A22B124Open-weight LLMs
Google Gemma 4186Open-weight LLMs
MoonshotAI Kimi K2.5227LLMs
z.ai GLM-5244LLMs

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 Swahili.

Real-time

The real-time models in Swahili are five MT engines, three LLM-based MT engines and the open-weight OpenAI gpt-oss-120b. Three of them made the shortlist, DeepL Next Gen, Google Translation LLM and Translated Lara 2, and translations from all three have 100% of the sentences in the formal register. None of the three meet formatting. Among the shortlisted LLMs, translations from OpenAI GPT-5.6 Luna are the fastest, at 15 seconds per 1,000 words in one step and 119 in three steps (translation + LQA + repair).

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

Tone of voice and gender-neutral English to Swahili translation

Tone of voice
Formal register
Gender-neutrality strategy
No grammatical gender for persons — 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
Anthropic Claude Fable 5three-step100%✓$617216
OpenAI GPT-5.6 Lunathree-step100%✓$543119
Near miss

Seven of the 11 shortlisted one-step solutions in Swahili meet tone of voice: those on OpenAI GPT-5.6 Luna, OpenAI GPT-4.1, DeepSeek V3.2, Anthropic Claude Sonnet 4.6, Google Translation LLM, DeepL Next Gen and Translated Lara 2. Those on Anthropic Claude Fable 5, Google Gemini 3.1 Pro Preview, Google Gemini 3.5 Flash and Google Gemma 4 have 97.9% of the sentences in the formal register, where we require 100%. Swahili has no grammatical gender for persons, so for gender neutrality we check only that translations avoid gendered terms.

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

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

Confidence

For the 11 shortlisted solutions in Swahili, the median share of sentences on which the three LQA judges agree is 90.4%, just over the 90% mark. So the Intento LQA error counts on this page carry weight. Three shortlisted solutions, on Anthropic Claude Sonnet 4.6, DeepL Next Gen and Translated Lara 2, have no conclusive Intento LQA result, and for them this page reports automatic scores, tone of voice, tag handling, formatting, cost and time.

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

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