Head-to-head comparison

GPT-5.6 Luna vs. Grok 4.5

Compare published benchmark results from matching versions and cohorts, API pricing, and technical specifications. Any documented test setup differences remain visible.

shared result series: 196
distinct benchmarks: 24
latest retrieval: 2026-09-04

First modelSecond model

Specifications

General specifications

Release date, availability, context window, architecture, and published parameter counts at a glance. Undisclosed details remain marked as unavailable.

Specifications for GPT-5.6 Luna and Grok 4.5
Attribute	GPT-5.6 Luna	Grok 4.5
Provider	OpenAI	xAI
Released	Jun 26, 2026	Jul 16, 2026
Availability	Active	Active
Model type	Proprietary	Proprietary
Parameters	Not published	Not published
Architecture	Not published	Not published
Context window	1,050,000 tokens	500,000 tokens
Knowledge cutoff	February 16, 2026	February 1, 2026
Technical sources	Model, Context, Knowledge cutoff	Model

Pricing

API pricing compared

The table compares official standard API rates per 1M tokens, including published cache pricing. Batch, fast, priority, regional surcharges, tool calls, and cloud platform pricing are excluded.

API pricing for GPT-5.6 Luna and Grok 4.5
Price type	GPT-5.6 Luna	Grok 4.5
API input	$0.2 ≤272K / $0.4 >272K	$2 ≤200K / $4 >200K
API output	$1.2 ≤272K / $1.8 >272K	$6 ≤200K / $12 >200K
Cache read	$0.02 ≤272K / $0.04 >272K	$0.3 ≤200K / $0.6 >200K
Cache write (5 min.)	$0.25 ≤272K / $0.5 >272K	Not listed
Cache write (1 hr.)	Not listed	Not listed
Price verified	08/11/2026 Source	08/11/2026 Source

GPT-5.6 LunaGrok 4.5

API inputUSD per 1M tokens, base tier

GPT-5.6 Luna$0.2

Grok 4.5$2

API outputUSD per 1M tokens, base tier

GPT-5.6 Luna$1.2

Grok 4.5$6

Cache readUSD per 1M tokens, base tier

GPT-5.6 Luna$0.02

Grok 4.5$0.3

Key to the marks:better valuebetter, but not conclusivetie

Pricing by provider

Direct developer pricing and provider endpoint tariffs routed through OpenRouter are listed separately. Prices are in USD per 1M tokens. Context-dependent direct tiers plus regional, Flex, Priority, and other OpenRouter tariffs remain individually identifiable.

Provider pricing for GPT-5.6 Luna and Grok 4.5
Model	Provider	Purchase route and tariff	Input per 1M tokens	Output per 1M tokens	Source
GPT-5.6 Luna	OpenAI	Direct from developerUp to 272,000 context tokens	$0.2	$1.2	Source08/11/2026
	OpenAI	Direct from developerAbove 272,000 context tokens	$0.4	$1.8	Source08/11/2026
	Amazon Bedrock	Via OpenRouteramazon-bedrock/us-east-1	$0.22	$1.32	Source09/06/2026
	Azure	Via OpenRouterazure	$0.2	$1.2	Source09/06/2026
	Azure	Via OpenRouterazure/eu	$0.22	$1.32	Source09/06/2026
	Azure	Via OpenRouterazure/us	$0.22	$1.32	Source09/06/2026
	OpenAI	Via OpenRouteropenai	$0.2	$1.2	Source09/06/2026
	OpenAI	Via OpenRouteropenai/fast	$0.4	$2.4	Source09/06/2026
	OpenAI	Via OpenRouteropenai/flex	Lowest listed price: $0.1	Lowest listed price: $0.6	Source09/06/2026
Grok 4.5	xAI	Direct from developerUp to 200,000 context tokens	Lowest listed price: $2	Lowest listed price: $6	Source08/11/2026
	xAI	Direct from developerAbove 200,000 context tokens	$4	$12	Source08/11/2026
	xAI	Via OpenRouterxai	Lowest listed price: $2	Lowest listed price: $6	Source09/06/2026
	xAI	Via OpenRouterxai/priority	$4	$12	Source09/06/2026
	xAI	Via OpenRouterxai/zdr	Lowest listed price: $2	Lowest listed price: $6	Source09/06/2026
	xAI	Via OpenRouterxai/zdr/priority	$4	$12	Source09/06/2026

Performance

Shared benchmarks

Only published results with the same benchmark version, task, metric, and comparison cohort are paired. Different reasoning levels, agents, harnesses, or output limits appear directly in the table.

Capability profile from matched benchmarks

Each axis averages directly matched benchmark families. A value of 100 means the stronger value within this pair, not a universal quality score.

GPT-5.6 Luna

Grok 4.5

Coding: 100 / 91.2 (4 benchmark families)

Reasoning: 98.6 / 100 (1 benchmark family)

Mathematics: 100 / 51.7 (1 benchmark family)

Knowledge: 96.4 / 100 (1 benchmark family)

Finance: 99.1 / 90.5 (5 benchmark families)

Legal: 67.9 / 100 (3 benchmark families)

Agentic tasks: 95.8 / 92.9 (2 benchmark families)

Multimodal: 100 / 72.7 (1 benchmark family)

25 matched rows from 23 benchmark families were considered. The radar shows 8 of 11 comparable categories.

GPT-5.6 LunaGrok 4.5

Code MigrationOverall. Higher is better. No documented setup difference

GPT-5.6 Luna44.55 %

Grok 4.536.596 %

CorpFin v2Overall. Higher is better. No documented setup difference

GPT-5.6 Luna64.219 %

Grok 4.567.405 %

EMBOverall. Higher is better. No documented setup difference

GPT-5.6 Luna67.116 %

Grok 4.552.911 %

Finance Agent (v2)Overall. Higher is better. No documented setup difference

GPT-5.6 Luna55.044 %

Grok 4.548.349 %

GPQA DiamondOverall. Higher is better. No documented setup difference

GPT-5.6 Luna91.666 %

Grok 4.592.929 %

Harvey's Legal Agent BenchmarkOverall · Task fully resolved. Higher is better. No documented setup difference

GPT-5.6 Luna1.25 %

Grok 4.512.917 %

Legal Research BenchOverall · All-pass. Higher is better. No documented setup difference

GPT-5.6 Luna36.538 %

Grok 4.537.981 %

LegalBenchOverall. Higher is better. No documented setup difference

GPT-5.6 Luna84.034 %

Grok 4.585.965 %

LMArena Text, Style ControlOverall. Higher is better. Test setup not documented as identical

GPT-5.6 Luna1,452.364

Grok 4.51,470.015

MedCodeOverall. Higher is better. No documented setup difference

GPT-5.6 Luna42.391 %

Grok 4.543.291 %

MedScribeOverall. Higher is better. No documented setup difference

GPT-5.6 Luna84.391 %

Grok 4.586.884 %

MMLU-ProOverall. Higher is better. No documented setup difference

GPT-5.6 Luna86.036 %

Grok 4.589.216 %

Key to the marks:better valuebetter, but not conclusivetie

Benchmark scores for GPT-5.6 Luna and Grok 4.5
Benchmark and task	GPT-5.6 Luna	Grok 4.5	Source
Code MigrationOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner44.55 %	36.596 %	Vals AI Source details Data as of: 09/03/2026
CorpFin v2Overall Test details No documented difference in the test setupVersion: 2Metric: accuracyScoring: Higher is better	64.219 %	Winner67.405 %	Vals AI Source details Data as of: 08/12/2026
EMBOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner67.116 %	52.911 %	Vals AI Source details Data as of: 09/03/2026
Finance Agent (v2)Overall Test details No documented difference in the test setupVersion: 2Metric: accuracyScoring: Higher is better	Winner55.044 %	48.349 %	Vals AI Source details Data as of: 09/03/2026
GPQA DiamondOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	91.666 %	Winner92.929 %	Vals AI Source details Data as of: 09/01/2026
Harvey's Legal Agent BenchmarkOverall · Task fully resolved Test details No documented difference in the test setupVersion: 1Metric: task resolution rateScoring: Higher is better	1.25 %	Winner12.917 %	Vals AI Source details Data as of: 09/03/2026
Legal Research BenchOverall · All-pass Test details No documented difference in the test setupVersion: 1Metric: all-pass rateScoring: Higher is better	36.538 %	Winner37.981 %	Vals AI Source details Data as of: 09/03/2026
LegalBenchOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	84.034 %	Winner85.965 %	Vals AI Source details Data as of: 09/01/2026
LMArena Text, Style ControlOverall Test details Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterGPT-5.6 Luna: Snapshot: gpt-5.6-luna-xhigh, Reasoning: xhigh, Harness: Arena text, style control Grok 4.5: Snapshot: grok-4.5, Harness: Arena text, style controlGPT-5.6 Luna: Style-controlled Arena rating from 24,433 anonymous pairwise votes.Grok 4.5: Style-controlled Arena rating from 25,873 anonymous pairwise votes.	1,452.364 95% confidence interval: ±5.03The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.	Higher measured value1,470.015 95% confidence interval: ±4.921The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.	LMArena Source details Data as of: 09/01/2026
MedCodeOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	42.391 %	Winner43.291 %	Vals AI Source details Data as of: 09/03/2026
MedScribeOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	84.391 %	Winner86.884 %	Vals AI Source details Data as of: 09/03/2026
MMLU-ProOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	86.036 %	Winner89.216 %	Vals AI Source details Data as of: 09/01/2026
MMMU-ProOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner85.029 %	61.792 %	Vals AI Source details Data as of: 09/01/2026
MortgageTaxOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner67.29 %	61.804 %	Vals AI Source details Data as of: 09/01/2026
ProgramBenchOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Tie0 %	Tie0 %	Vals AI Source details Data as of: 09/01/2026
ProofBenchOverall Test details No documented difference in the test setupVersion: 1.1Metric: accuracyScoring: Higher is better	Winner60 %	31 %	Vals AI Source details Data as of: 09/01/2026
SAGEOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner44.22 %	34.967 %	Vals AI Source details Data as of: 09/03/2026
SkillsBenchOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is betterSettings: Harness: OpenHands	60.447 %	Winner66.034 %	Vals AI Source details Data as of: 09/01/2026
SWE-bench VerifiedOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner93 %	86.6 %	Vals AI Source details Data as of: 09/01/2026
TaxEval v2Overall Test details No documented difference in the test setupVersion: 2Metric: accuracyScoring: Higher is better	Winner76.166 %	71.668 %	Vals AI Source details Data as of: 09/01/2026
Terminal-Bench 2.1Overall Test details No documented difference in the test setupVersion: 2.1Metric: accuracyScoring: Higher is better	Winner79.026 %	67.79 %	Vals AI Source details Data as of: 09/03/2026
Vals IndexOverall Test details No documented difference in the test setupVersion: 2Metric: weighted index scoreScoring: Higher is better	Winner59.881 %	51.528 %	Vals AI Source details Data as of: 09/03/2026
Vals Multimodal IndexOverall Test details No documented difference in the test setupVersion: 1.2Metric: weighted index scoreScoring: Higher is better	Winner69.058 %	63.42 %	Vals AI Source details Data as of: 08/11/2026
Vibe Code Bench v1.1Overall Test details No documented difference in the test setupVersion: 1.1Metric: accuracyScoring: Higher is betterSettings: Harness: OpenHands	Winner77.055 %	69.002 %	Vals AI Source details Data as of: 09/03/2026
Code MigrationCLI Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	Higher measured value36.067 %	25.461 %	Vals AI Source details Data as of: 08/09/2026
CorpFin v2Exact Pages Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	63.52 %	Higher measured value66.317 %	Vals AI Source details Data as of: 08/06/2026
EMBComps Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	Higher measured value54.573 %	39.489 %	Vals AI Source details Data as of: 08/06/2026
Finance Agent (v2)Adjustments Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	Higher measured value52.027 %	38.568 %	Vals AI Source details Data as of: 08/06/2026
GPQA DiamondFew-Shot CoT Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	92.424 %	Higher measured value92.929 %	Vals AI Source details Data as of: 08/09/2026
Harvey's Legal Agent BenchmarkAntitrust Competition · Criteria passed Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: criteria pass rateScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	85.145 %	Higher measured value87.319 %	Vals AI Source details Data as of: 08/07/2026
Legal Research BenchAdministrative / Regulatory · All-pass Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: all-pass rateScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	48.485 %	Higher measured value51.515 %	Vals AI Source details Data as of: 08/06/2026
LegalBenchConclusion Tasks Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	88.864 %	Higher measured value89.507 %	Vals AI Source details Data as of: 08/09/2026
LMArena Text, Style ControlBusiness, management and finance Test details Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterGPT-5.6 Luna: Snapshot: gpt-5.6-luna-xhigh, Reasoning: xhigh, Harness: Arena text, style control Grok 4.5: Snapshot: grok-4.5, Harness: Arena text, style controlGPT-5.6 Luna: Style-controlled Arena rating from 4,691 anonymous pairwise votes.Grok 4.5: Style-controlled Arena rating from 5,122 anonymous pairwise votes.	1,461.709 95% confidence interval: ±9.371The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.	Higher measured value1,465.734 95% confidence interval: ±8.936The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.	LMArena Source details Data as of: 09/01/2026
MMLU-ProBiology Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	93.305 %	Higher measured value94.282 %	Vals AI Source details Data as of: 08/09/2026
MortgageTaxNumerical Extraction Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	Higher measured value75.596 %	62.798 %	Vals AI Source details Data as of: 08/09/2026
ProgramBenchAlmost Resolved Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	Higher measured value9 %	4.5 %	Vals AI Source details Data as of: 08/09/2026
SAGEAutomata Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 30,000 tokens Grok 4.5: Reasoning: high, Temperature: 1, Top P: 0.95, Output limit: 30,000 tokens	31.35 %	Higher measured value32.54 %	Vals AI Source details Data as of: 08/09/2026
SkillsBenchNo Skills Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Harness: OpenHands, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Harness: OpenHands, Temperature: 0.7, Top P: 0.95	45.189 %	Higher measured value48.808 %	Vals AI Source details Data as of: 08/07/2026
SWE-bench Verified<15 min fix Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	Higher measured value96.392 %	93.814 %	Vals AI Source details Data as of: 08/08/2026
TaxEval v2Correctness Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	Higher measured value66.558 %	62.551 %	Vals AI Source details Data as of: 08/09/2026
Terminal-Bench 2.1Easy Test details Test setup not documented as identicalNo direct winnerVersion: 2.1Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	83.333 %	Higher measured value91.667 %	Vals AI Source details Data as of: 08/06/2026
Vals IndexCorpFin v2 Test details Test setup not documented as identicalNo direct winnerVersion: 1.2Metric: benchmark scoreScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	65.035 %	Higher measured value68.415 %	Vals AI Source details Data as of: 08/09/2026
Vals Multimodal IndexCorpFin v2 Test details Test setup not documented as identicalNo direct winnerVersion: 1.2Metric: benchmark scoreScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	65.035 %	Higher measured value68.415 %	Vals AI Source details Data as of: 08/09/2026
Code MigrationCOBOL Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	No direct winner70 %	No direct winner70 %	Vals AI Source details Data as of: 08/09/2026
CorpFin v2Max Fitting Context Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	64.103 %	Higher measured value67.483 %	Vals AI Source details Data as of: 08/06/2026
EMBDataroom Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	Higher measured value83.009 %	64.953 %	Vals AI Source details Data as of: 08/06/2026
Finance Agent (v2)All-Pass Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	Higher measured value43.285 %	36.743 %	Vals AI Source details Data as of: 08/06/2026
GPQA DiamondZero-Shot CoT Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	90.909 %	Higher measured value92.929 %	Vals AI Source details Data as of: 08/09/2026
Harvey's Legal Agent BenchmarkAntitrust Competition · Task fully resolved Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: task resolution rateScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	No direct winner0 %	No direct winner0 %	Vals AI Source details Data as of: 08/07/2026
Legal Research BenchAdministrative / Regulatory · Weighted partial credit Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: weighted partial-credit scoreScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	87.513 %	Higher measured value88.75 %	Vals AI Source details Data as of: 08/06/2026
LegalBenchInterpretation Tasks Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	82.142 %	Higher measured value83.22 %	Vals AI Source details Data as of: 08/09/2026
LMArena Text, Style ControlChinese Test details Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterGPT-5.6 Luna: Snapshot: gpt-5.6-luna-xhigh, Reasoning: xhigh, Harness: Arena text, style control Grok 4.5: Snapshot: grok-4.5, Harness: Arena text, style controlGPT-5.6 Luna: Style-controlled Arena rating from 1,691 anonymous pairwise votes.Grok 4.5: Style-controlled Arena rating from 1,737 anonymous pairwise votes.	1,474.185 95% confidence interval: ±15.484The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.	Higher measured value1,512.8 95% confidence interval: ±15.002The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.	LMArena Source details Data as of: 09/01/2026
MMLU-ProBusiness Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	91.001 %	Higher measured value93.283 %	Vals AI Source details Data as of: 08/09/2026
MortgageTaxSemantic Extraction Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	58.983 %	Higher measured value60.811 %	Vals AI Source details Data as of: 08/09/2026
ProgramBenchFully Resolved Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	No direct winner0 %	No direct winner0 %	Vals AI Source details Data as of: 08/09/2026
SAGECalculus Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 30,000 tokens Grok 4.5: Reasoning: high, Temperature: 1, Top P: 0.95, Output limit: 30,000 tokens	Higher measured value64.506 %	59.568 %	Vals AI Source details Data as of: 08/09/2026
SkillsBenchWith Skills Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Harness: OpenHands, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Harness: OpenHands, Temperature: 0.7, Top P: 0.95	60.447 %	Higher measured value66.034 %	Vals AI Source details Data as of: 08/07/2026
SWE-bench Verified>4 hours Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	No direct winner66.667 %	No direct winner66.667 %	Vals AI Source details Data as of: 08/08/2026
TaxEval v2Stepwise Reasoning Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	Higher measured value85.773 %	80.785 %	Vals AI Source details Data as of: 08/09/2026
Terminal-Bench 2.1Hard Test details Test setup not documented as identicalNo direct winnerVersion: 2.1Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	Higher measured value70 %	56.667 %	Vals AI Source details Data as of: 08/06/2026
Vals IndexFinance Agent v2 Test details Test setup not documented as identicalNo direct winnerVersion: 1.2Metric: benchmark scoreScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	Higher measured value55.555 %	48.751 %	Vals AI Source details Data as of: 08/09/2026
Vals Multimodal IndexFinance Agent v2 Test details Test setup not documented as identicalNo direct winnerVersion: 1.2Metric: benchmark scoreScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	Higher measured value55.555 %	48.751 %	Vals AI Source details Data as of: 08/09/2026
Code MigrationCode Quality Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: mean reviewer code-quality ratingScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	3.195 / 5	Higher measured value4.078 / 5	Vals AI Source details Data as of: 08/09/2026
CorpFin v2Shared Max Context Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterGPT-5.6 Luna: Reasoning: max, Output limit: 128,000 tokens Grok 4.5: Reasoning: high, Temperature: 0.7, Top P: 0.95	65.035 %	Higher measured value68.415 %	Vals AI Source details Data as of: 08/06/2026
Key to the marks:better valuebetter, but not conclusivetie

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Your workload, budget, and required context length matter most. A coding benchmark says little about visual understanding or agent performance.

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