The State of Translation Automation 2026 · Languages

English to Sinhala AI translation quality, cost and speed

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

Key findings on English to Sinhala translation

  1. 1Near missThe one-step solution on Anthropic Claude Fable 5 meets every Standard requirement in Sinhala except tag handling, with 99.2% of the tags right. The two-step solution (translation + post-edit) on the same model has 100% of the tags right and meets them all.See the data →
  2. 2Level step-upSolutions on five models meet every Basic requirement in Sinhala, and the Standard requirements keep two. Those on Google Gemini 3.1 Pro Preview, Google Gemini 3.5 Flash and DeepSeek V3.2 that meet general translation quality have 97.9% of the sentences in the formal register, where tone of voice asks for 100%.See the data →

Find English to Sinhala 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 Sinhala, 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 Sinhala translation

Trade-off

Two solutions meet every Standard requirement in Sinhala, and neither leads on errors, cost and time at once. The three-step solution (translation + LQA + repair) on OpenAI GPT-5.6 Luna has 14.3 total errors per 1,000 words against 20.9 for the two-step solution (translation + post-edit) on Anthropic Claude Fable 5. It takes 136 seconds per 1,000 words against 247, and costs $556 per million characters against $46.00. Optimize for selects OpenAI GPT-5.6 Luna for quality and latency, and Anthropic Claude Fable 5 for cost.

Constraints

With one step only, the solutions on Google Gemini 3.1 Pro Preview, at $5.77 per million characters and 82 seconds per 1,000 words, and Anthropic Claude Fable 5, at $46.00 and 247 seconds, meet every Basic requirement. None of the real-time solutions meet even the Basic requirements.

Agent effect

For the Advanced requirements, the gender-neutrality agent works with both solutions that meet every Standard requirement. On OpenAI GPT-5.6 Luna it raises the cost from $556 to $926 per million characters and the time from 136 to 147 seconds per 1,000 words, and total errors fall from 14.3 to 10.6 per 1,000 words. On Anthropic Claude Fable 5 the cost goes from $46.00 to $93.29 per million characters, the time from 247 to 514 seconds per 1,000 words and total errors from 20.9 to 17.5 per 1,000 words.

English to Sinhala translation quality levels

Optimize for
Basic requirements★★☆☆☆

Tier 1: simple solution + backup

Solutions that meet them
5 (2 one-step)
Simplest solution
one-step
Fewest errors

OpenAI GPT-5.6 Luna
three-step

Total errors per 1,000 words
14.3
Cost per million characters
$556
Seconds per 1,000 words
136
Lowest cost

Google Gemini 3.1 Pro Preview
one-step LLM adjusted for Standard requirements

Total errors per 1,000 words
23.6
Cost per million characters
$5.77
Seconds per 1,000 words
82
Shortest time

Google Gemini 3.1 Pro Preview
one-step LLM adjusted for Standard requirements

Total errors per 1,000 words
23.6
Cost per million characters
$5.77
Seconds per 1,000 words
82
Standard requirements☆☆

Tier 2: two or more solutions, none simple

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

OpenAI GPT-5.6 Luna
three-step

Total errors per 1,000 words
14.3
Cost per million characters
$556
Seconds per 1,000 words
136
Lowest cost

Anthropic Claude Fable 5
two-step

Total errors per 1,000 words
20.9
Cost per million characters
$46.00
Seconds per 1,000 words
247
Shortest time

OpenAI GPT-5.6 Luna
three-step

Total errors per 1,000 words
14.3
Cost per million characters
$556
Seconds per 1,000 words
136
Advanced requirements

Tier 4: no solution

Solutions that meet them
0
Best available

OpenAI GPT-5.6 Luna
three-step with the gender-neutrality agent

Misses tone of voice, gender neutrality.

Total errors per 1,000 words
10.6
Cost per million characters
$926
Seconds per 1,000 words
147

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 1: simple solution + backup★★ ☆☆☆one-stepGoogle Gemini 3.1 Pro Preview23.6$5.7782
StandardTier 2: two or more solutions, none simple☆☆two-stepAnthropic Claude Fable 520.9$46247
AdvancedTier 4: no solutionNo solution———

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

Under the Basic requirements, the solutions on Google Gemini 3.1 Pro Preview and Anthropic Claude Fable 5 take one step, and the other three are three-step solutions (translation + LQA + repair). The Standard requirements remove three of the five models on tone of voice and take Anthropic Claude Fable 5 to two steps (translation + post-edit). Optimize for selects OpenAI GPT-5.6 Luna for quality under both sets of requirements, and Google Gemini 3.1 Pro Preview for cost and latency under the Basic ones.

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

English to Sinhala translation cost against errors

Chart data
Cost and weighted errors of the one-step solutions in Sinhala
ModelUS dollars per million charactersWeighted errors per 1,000 wordsGroup
Google Gemma 40.1760Misses a Standard requirement
OpenAI GPT-5.6 Luna0.6329.7Misses a Standard requirement
DeepSeek V3.21.8753.4Misses a Standard requirement
Google Gemini 3.5 Flash4.3734.3Misses a Standard requirement
Google Gemini 3.1 Pro Preview5.7719.8Misses a Standard requirement
OpenAI GPT-5.515.6231.6Misses a Standard requirement
Google Cloud Advanced Translation API20119Misses a Standard requirement
Anthropic Claude Opus 4.822.8832.3Misses a Standard requirement
Translated Lara 224.9987.7Misses a Standard requirement
Anthropic Claude Fable 54617.1Misses a Standard requirement
Price vs quality

Of the shortlisted one-step solutions in Sinhala with a conclusive Intento LQA result, a higher price comes with fewer weighted errors only along four of them: from the open-weight Google Gemma 4, the cheapest, at $0.17 per million characters and 60.0 weighted errors per 1,000 words, through the LLMs OpenAI GPT-5.6 Luna at $0.63 and 29.7 and Google Gemini 3.1 Pro Preview at $5.77 and 19.8, to Anthropic Claude Fable 5 at $46.00 and 17.1. Each of the others has more weighted errors than a cheaper one.

How we measure it: 11-01 · 10-10

English to Sinhala translation requirements

Chart data
Errors per 1,000 words of the one-step solutions in Sinhala, median, by requirement
RequirementMedian errors per 1,000 words
General translation quality33.3
Gender neutrality3.3
Tone of voice0.1
Tag handling0

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

Bottleneck

General translation quality holds back most solutions in Sinhala. Besides the two that meet it, the one-step solutions with a conclusive result have 29.7 to 119.0 weighted errors per 1,000 words. Three-step solutions (translation + LQA + repair) bring OpenAI GPT-5.6 Luna, DeepSeek V3.2 and Google Gemini 3.5 Flash under the bar, at 11.2, 13.5 and 17.8 weighted errors per 1,000 words. The one-step solution on Translated Lara 2 meets tone of voice and tag handling, and the one on Google Cloud Advanced Translation API meets neither.

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

AI models and MT engines for English to Sinhala translation

Chart data
Weighted errors per 1,000 words of the shortlisted one-step solutions in Sinhala
ModelWeighted errors per 1,000 words of the shortlisted one-step solutions in SinhalaClass
Google Cloud Advanced Translation API119MT engines
Translated Lara 287.7LLM-based MT engines
Google Gemma 460Open-weight LLMs
DeepSeek V3.253.4LLMs
Google Gemini 3.5 Flash34.3LLMs
Anthropic Claude Opus 4.832.3LLMs
OpenAI GPT-5.531.6LLMs
OpenAI GPT-5.6 Luna29.7LLMs
Google Gemini 3.1 Pro Preview19.8LLMs
Anthropic Claude Fable 517.1LLMs

No translation into Sinhala: AI21 Jamba Large 1.7 (cut off part-way, garbage or near-empty, wrong language, wrong script).

Model types

In one step, translations from the eight shortlisted LLMs with a conclusive Intento LQA result have 17.1 to 60.0 weighted errors per 1,000 words, the most from the open-weight Google Gemma 4. Translations from Translated Lara 2, an LLM-based MT engine, have 87.7 weighted errors per 1,000 words and 29 major errors, and those from the MT engine Google Cloud Advanced Translation API 119.0, with 8 critical errors, the only ones in the 10 one-step solutions with a conclusive result. All eight LLMs support Sinhala by our measured criteria.

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

How we shortlisted English to Sinhala translation solutions

Chart data
Ranks of the models on the two automatic metrics, Sinhala
ModelCOMET-KiwiRank on COMET-KiwiMetricXRank on MetricXShortlistedShortlist place
Anthropic Claude Sonnet 50.850101.5510NoNot shortlisted
MoonshotAI Kimi K2.50.847121.7713NoNot shortlisted
Anthropic Claude Sonnet 4.60.846131.5711NoNot shortlisted
xAI Grok 4.20 (non-reasoning)0.841141.7714NoNot shortlisted
OpenAI GPT-4.10.836151.8215NoNot shortlisted
ModernMT Enterprise Edition0.801182.7520NoNot shortlisted
OpenAI gpt-oss-120b0.798192.4517NoNot shortlisted
Amazon Translate0.794202.5218NoNot shortlisted
Yandex Cloud Translate v20.787212.8321NoNot shortlisted
MiniMax M2.50.769223.5623NoNot shortlisted
Anthropic Claude Haiku 4.50.753233.5322NoNot shortlisted
Mistral Large 30.724243.7124NoNot shortlisted
Alibaba Qwen3-235B-A22B0.702254.1625NoNot shortlisted
Swiss AI Apertus-8B-25090.4672611.5127NoNot shortlisted
Alibaba Machine Translation API0.4542710.5526NoNot shortlisted
Cohere Command A Translate0.4112813.0728NoNot shortlisted
Mistral Medium 3.10.3822913.3629NoNot shortlisted
Google Gemini 3.5 Flash0.87411.131YesTop 8 by both metrics
Google Gemini 3.1 Pro Preview0.87421.142YesTop 8 by both metrics
OpenAI GPT-5.6 Luna0.87131.274YesTop 8 by both metrics
Google Gemma 40.86941.273YesTop 8 by both metrics
OpenAI GPT-5.50.86551.509YesTop 8 by COMET-Kiwi
z.ai GLM-50.86261.386YesTop 8 by both metrics
Anthropic Claude Fable 50.86071.295YesTop 8 by both metrics
Anthropic Claude Opus 4.80.85881.397YesTop 8 by both metrics
Translated Lara 20.85191.5812YesReal-time place
DeepSeek V3.20.848111.448YesTop 8 by MetricX
Microsoft Translator0.817161.9216YesReal-time place
Google Cloud Advanced Translation API0.814172.5619YesReal-time place
ModelSolution complexityCOMET-Kiwi rankCOMET-KiwiMetricX rankMetricXShortlist
Google Gemini 3.5 FlashAdjusted LLM10.87411.13Top 8 by both metrics
Google Gemini 3.1 Pro PreviewAdjusted LLM20.87421.14Top 8 by both metrics
OpenAI GPT-5.6 LunaAdjusted LLM30.87141.27Top 8 by both metrics
Google Gemma 4Adjusted LLM40.86931.27Top 8 by both metrics
OpenAI GPT-5.5Adjusted LLM50.86591.50Top 8 by COMET-Kiwi
z.ai GLM-5Adjusted LLM60.86261.38Top 8 by both metrics
Anthropic Claude Fable 5Adjusted LLM70.86051.29Top 8 by both metrics
Anthropic Claude Opus 4.8Adjusted LLM80.85871.39Top 8 by both metrics
Translated Lara 2Adjusted NMT90.851121.58Real-time place
Anthropic Claude Sonnet 5Adjusted LLM100.850101.55Not shortlisted
DeepSeek V3.2Adjusted LLM110.84881.44Top 8 by MetricX
MoonshotAI Kimi K2.5Adjusted LLM120.847131.77Not shortlisted
Anthropic Claude Sonnet 4.6Adjusted LLM130.846111.57Not shortlisted
xAI Grok 4.20 (non-reasoning)Adjusted LLM140.841141.77Not shortlisted
OpenAI GPT-4.1Adjusted LLM150.836151.82Not shortlisted
Microsoft TranslatorOff-the-shelf NMT160.817161.92Real-time place
Google Cloud Advanced Translation APIOff-the-shelf NMT170.814192.56Real-time place
ModernMT Enterprise EditionOff-the-shelf NMT180.801202.75Not shortlisted
OpenAI gpt-oss-120bAdjusted LLM190.798172.45Not shortlisted
Amazon TranslateOff-the-shelf NMT200.794182.52Not shortlisted
Yandex Cloud Translate v2Off-the-shelf NMT210.787212.83Not shortlisted
MiniMax M2.5Adjusted LLM220.769233.56Not shortlisted
Anthropic Claude Haiku 4.5Off-the-shelf LLM230.753223.53Not shortlisted
Mistral Large 3Adjusted LLM240.724243.71Not shortlisted
Alibaba Qwen3-235B-A22BAdjusted LLM250.702254.16Not shortlisted
Swiss AI Apertus-8B-2509Off-the-shelf LLM260.4672711.51Not shortlisted
Alibaba Machine Translation APIOff-the-shelf NMT270.4542610.55Not shortlisted
Cohere Command A TranslateAdjusted LLM280.4112813.07Not shortlisted
Mistral Medium 3.1Adjusted LLM290.3822913.36Not shortlisted
OpenAI GPT-5.6 SolAdjusted LLM—0.870—1.20Same model family as OpenAI GPT-5.6 Luna
OpenAI GPT-5.6 TerraAdjusted LLM—0.862—1.36Same model family as OpenAI GPT-5.6 Luna
xAI Grok 4.20 (reasoning)Adjusted LLM—0.840—1.95Same model family as xAI Grok 4.20 (non-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 29 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

COMET-Kiwi put OpenAI GPT-5.5 on the shortlist, fifth on COMET-Kiwi and ninth on MetricX, and MetricX put DeepSeek V3.2 there, eighth on MetricX and 11th on COMET-Kiwi. By Intento LQA, the one-step solutions on them have 31.6 and 53.4 weighted errors per 1,000 words, and the three-step solution (translation + LQA + repair) on DeepSeek V3.2 meets every Basic requirement. Nearest the cut in the tail is Anthropic Claude Sonnet 5, at rank 10 on both metrics.

How we measure it: 00-08 · 00-09

English to Sinhala translation cost

Quality levelCheapest solution that meets every requirement of the levelCost per million characters
BasicGoogle Gemini 3.1 Pro Preview, one-step LLM adjusted for Standard requirements$5.77
StandardAnthropic Claude Fable 5, two-step$46.00
AdvancedNo solution—
Chart data
Cost of the shortlisted one-step solutions in Sinhala
ModelUS dollars per million charactersClass
Google Gemma 4$0.17Open-weight LLMs
OpenAI GPT-5.6 Luna$0.63LLMs
DeepSeek V3.2$1.87LLMs
Google Gemini 3.5 Flash$4.37LLMs
Google Gemini 3.1 Pro Preview$5.77LLMs
z.ai GLM-5$6.39LLMs
Microsoft Translator$10MT engines
OpenAI GPT-5.5$15.62LLMs
Google Cloud Advanced Translation API$20MT engines
Anthropic Claude Opus 4.8$22.88LLMs
Translated Lara 2$24.99LLM-based MT engines
Anthropic Claude Fable 5$46LLMs
Chart data
Tokens per character of the translation into Sinhala, by model
ModelTokens per characterClass
Cohere Command A Translate1.423LLMs
Mistral Large 31.366LLMs
z.ai GLM-51.364LLMs
Mistral Medium 3.11.349LLMs
Alibaba Qwen3-235B-A22B1.131Open-weight LLMs
MiniMax M2.51.03LLMs
Anthropic Claude Fable 50.837LLMs
Anthropic Claude Opus 4.80.835LLMs
Anthropic Claude Sonnet 50.822LLMs
OpenAI GPT-4.10.817LLMs
Anthropic Claude Haiku 4.50.809LLMs
Anthropic Claude Sonnet 4.60.805LLMs
DeepSeek V3.20.771LLMs
xAI Grok 4.20 (non-reasoning)0.738LLMs
xAI Grok 4.20 (reasoning)0.738LLMs
MoonshotAI Kimi K2.50.7LLMs
OpenAI GPT-5.6 Sol0.489LLMs
OpenAI GPT-5.50.485LLMs
OpenAI GPT-5.6 Luna0.484LLMs
OpenAI GPT-5.6 Terra0.484LLMs
Google Gemma 40.416Open-weight LLMs
Google Gemini 3.1 Pro Preview0.415LLMs
Google Gemini 3.5 Flash0.413LLMs
Cost driver

The tokenizers produce a median 0.81 tokens per character of Sinhala. On the same tokenizer, Sinhala has a median 3.1 times the tokens per character of the English source. The tokenizers of the two shortlisted Anthropic Claude models produce 0.835 and 0.837 tokens per character, those of the three shortlisted Google LLMs 0.413 to 0.416. The one-step solution on Google Gemini 3.1 Pro Preview costs $5.77 per million characters, the two-step one (translation + post-edit) $26.52 and the three-step one (translation + LQA + repair) $582.

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

English to Sinhala translation speed

Quality levelFastest solution that meets every requirement of the levelSeconds per 1,000 words
BasicGoogle Gemini 3.1 Pro Preview, one-step LLM adjusted for Standard requirements82
StandardOpenAI GPT-5.6 Luna, three-step136
AdvancedNo solution—
Chart data
Time to translate 1,000 words into Sinhala, by model
ModelSeconds per 1,000 wordsClass
Microsoft Translator0.2MT engines
Google Cloud Advanced Translation API0.2MT engines
ModernMT Enterprise Edition0.4MT engines
Amazon Translate1.3MT engines
Yandex Cloud Translate v23.2MT engines
OpenAI gpt-oss-120b3.3Open-weight LLMs
Translated Lara 26.4LLM-based MT engines
OpenAI GPT-5.6 Luna23LLMs
Alibaba Machine Translation API29MT engines
OpenAI GPT-4.144LLMs
xAI Grok 4.20 (non-reasoning)47LLMs
Google Gemini 3.5 Flash67LLMs
OpenAI GPT-5.6 Terra72LLMs
Anthropic Claude Haiku 4.579LLMs
Google Gemini 3.1 Pro Preview82LLMs
DeepSeek V3.287LLMs
xAI Grok 4.20 (reasoning)100LLMs
Cohere Command A Translate126LLMs
MiniMax M2.5127LLMs
Swiss AI Apertus-8B-2509137Open-weight LLMs
Anthropic Claude Sonnet 4.6148LLMs
Google Gemma 4188Open-weight LLMs
Anthropic Claude Sonnet 5221LLMs
OpenAI GPT-5.5222LLMs
OpenAI GPT-5.6 Sol226LLMs
Anthropic Claude Fable 5247LLMs
Anthropic Claude Opus 4.8275LLMs
Mistral Large 3330LLMs
MoonshotAI Kimi K2.5349LLMs
Alibaba Qwen3-235B-A22B403Open-weight LLMs
z.ai GLM-5705LLMs
Mistral Medium 3.12,192LLMs

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 Sinhala.

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

Tone of voice and gender-neutral English to Sinhala translation

Tone of voice
Formal register, with ඔබ
Gender-neutrality strategy
neutral nouns + neutral rephrasing
Options in the language
masculine default, explicit double forms, neutral nouns + neutral rephrasing
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 Lunathree-step, with the gender-neutrality agent98.2%✗$926147
Anthropic Claude Fable 5two-step, with the gender-neutrality agent100%✗$93.29514
Near miss

For Sinhala we check the formal register, with ඔබ as the form of address, and gender-neutral wording through neutral nouns and rephrasing, with no default gender. With the gender-neutrality agent, the two best solutions have 97.9% of the sentences in the formal register, against 100% without, so neither meets tone of voice. The one on Anthropic Claude Fable 5, a two-step solution (translation + post-edit), does not meet tag handling either, with 100% of the sentences about people gender-neutral but 99.6% of the tags right.

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

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

Confidence

Both pairs of automatic metrics agree in Sinhala above the threshold, and neither pair is borderline. The three LQA judges agree on a median of 94.7% of the sentences across the 12 shortlisted solutions. With agreement that high, the Intento LQA error counts on this page carry weight.

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

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