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Head-to-head comparison

GPT-6 Luna vs. Grok 4.6

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

shared result series
17
distinct benchmarks
17
latest retrieval
2026-09-23

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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-6 Luna and Grok 4.6
AttributeGPT-6 LunaGrok 4.6
ProviderOpenAIxAI
ReleasedSep 22, 2026Aug 12, 2026
AvailabilityActiveActive
Model typeProprietaryProprietary
ParametersNot publishedNot published
ArchitectureNot publishedNot published
Context window1,050,000 tokens500,000 tokens
Knowledge cutoffMay 18, 2026February 1, 2026
Technical sourcesModel, ContextModel

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-6 Luna and Grok 4.6
Price typeGPT-6 LunaGrok 4.6
API input$0.1 ≤272K / $0.2 >272K$2 ≤200K / $4 >200K
API output$0.5 ≤272K / $0.75 >272K$6 ≤200K / $12 >200K
Cache read$0.01 ≤272K / $0.02 >272K$0.5 ≤200K / $1 >200K
Cache write (5 min.)$0.13 ≤272K / $0.25 >272KNot listed
Cache write (1 hr.)Not listedNot listed
Price verified09/22/2026 Source09/22/2026 Source
GPT-6 LunaGrok 4.6
API inputUSD per 1M tokens, base tier
GPT-6 LunaLower price$0.1
Grok 4.6$2
API outputUSD per 1M tokens, base tier
GPT-6 LunaLower price$0.5
Grok 4.6$6
Cache readUSD per 1M tokens, base tier
GPT-6 LunaLower price$0.01
Grok 4.6$0.5

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-6 Luna and Grok 4.6
ModelProviderPurchase route and tariffInput per 1M tokensOutput per 1M tokensSource
GPT-6 LunaOpenAIDirect from developerUp to 272,000 context tokens$0.1Lowest listed price: $0.5Source09/22/2026
OpenAIDirect from developerAbove 272,000 context tokens$0.2$0.75Source09/22/2026
Amazon BedrockVia OpenRouteramazon-bedrock/us-east-1$0.11$0.55Source09/23/2026
AzureVia OpenRouterazure/eu$0.11$0.55Source09/23/2026
AzureVia OpenRouterazure/us$0.11$0.55Source09/23/2026
OpenAIVia OpenRouteropenaiLowest listed price: $0.1Lowest listed price: $0.5Source09/23/2026
OpenAIVia OpenRouteropenai/fast$0.2$1Source09/23/2026
Grok 4.6xAIDirect from developerUp to 200,000 context tokensLowest listed price: $2Lowest listed price: $6Source09/22/2026
xAIDirect from developerAbove 200,000 context tokens$4$12Source09/22/2026
Amazon BedrockVia OpenRouteramazon-bedrock/us-west-2$2.2$6.6Source09/23/2026
xAIVia OpenRouterxaiLowest listed price: $2Lowest listed price: $6Source09/23/2026
xAIVia OpenRouterxai/priority$4$12Source09/23/2026
xAIVia OpenRouterxai/zdrLowest listed price: $2Lowest listed price: $6Source09/23/2026
xAIVia OpenRouterxai/zdr/priority$4$12Source09/23/2026

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.

255075100CodingMathematicsFinanceLegalAgentic tasksProductivityHealthEducation
GPT-6 Luna
Grok 4.6
Coding: 98.5 / 93 (3 benchmark families)
Mathematics: 100 / 79.7 (1 benchmark family)
Finance: 92 / 97.2 (3 benchmark families)
Legal: 40.7 / 100 (2 benchmark families)
Agentic tasks: 93.3 / 100 (1 benchmark family)
Productivity: 86.2 / 100 (1 benchmark family)
Health: 98.3 / 100 (2 benchmark families)
Education: 100 / 60.1 (1 benchmark family)

17 matched rows from 17 benchmark families were considered. The radar shows 8 of 10 comparable categories.

GPT-6 LunaGrok 4.6
BioMysteryBenchOverall. Higher is better. No documented setup difference
GPT-6 Luna61.481 %
Grok 4.6Winner72.222 %
Code MigrationOverall. Higher is better. No documented setup difference
GPT-6 Luna42.554 %
Grok 4.6Winner44.572 %
EMBOverall. Higher is better. No documented setup difference
GPT-6 LunaWinner68.515 %
Grok 4.662.727 %
Finance Agent (v2)Overall. Higher is better. No documented setup difference
GPT-6 Luna49.873 %
Grok 4.6Winner53.682 %
Harvey's Legal Agent BenchmarkOverall · Task fully resolved. Higher is better. No documented setup difference
GPT-6 Luna2.917 %
Grok 4.6Winner15.833 %
IOIOverall. Higher is better. No documented setup difference
GPT-6 LunaWinner55.556 %
Grok 4.647.611 %
Legal Research BenchOverall · All-pass. Higher is better. No documented setup difference
GPT-6 Luna30.288 %
Grok 4.6Winner48.077 %
MedCodeOverall. Higher is better. No documented setup difference
GPT-6 Luna44.685 %
Grok 4.6Winner44.712 %
MedScribeOverall. Higher is better. No documented setup difference
GPT-6 Luna83.71 %
Grok 4.6Winner86.534 %
MysteryMechanismOverall. Higher is better. No documented setup difference
GPT-6 Luna19.369 %
Grok 4.6Winner30.631 %
ProofBenchOverall. Higher is better. No documented setup difference
GPT-6 LunaWinner64 %
Grok 4.651 %
Public Benefits Bench v1.1Overall. Higher is better. No documented setup difference
GPT-6 Luna57.645 %
Grok 4.6Winner66.847 %

Key to the marks:better valuebetter, but not conclusivetie

Benchmark scores for GPT-6 Luna and Grok 4.6
Benchmark and taskGPT-6 LunaGrok 4.6Source
BioMysteryBenchOverall
Test details
No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is betterSettings: Harness: Terminus 2
61.481 %
Winner72.222 %
Vals AI
Source details
Data as of: 09/22/2026
Code MigrationOverall
Test details
No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better
42.554 %
Winner44.572 %
Vals AI
Source details
Data as of: 09/22/2026
EMBOverall
Test details
No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better
Winner68.515 %
62.727 %
Vals AI
Source details
Data as of: 09/22/2026
Finance Agent (v2)Overall
Test details
No documented difference in the test setupVersion: 2Metric: accuracyScoring: Higher is better
49.873 %
Winner53.682 %
Vals AI
Source details
Data as of: 09/22/2026
Harvey's Legal Agent BenchmarkOverall · Task fully resolved
Test details
No documented difference in the test setupVersion: 1Metric: task resolution rateScoring: Higher is better
2.917 %
Winner15.833 %
Vals AI
Source details
Data as of: 09/22/2026
IOIOverall
Test details
No documented difference in the test setupVersion: 2Metric: accuracyScoring: Higher is better
Winner55.556 %
47.611 %
Vals AI
Source details
Data as of: 09/22/2026
Legal Research BenchOverall · All-pass
Test details
No documented difference in the test setupVersion: 1Metric: all-pass rateScoring: Higher is better
30.288 %
Winner48.077 %
Vals AI
Source details
Data as of: 09/22/2026
MedCodeOverall
Test details
No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better
44.685 %
Winner44.712 %
Vals AI
Source details
Data as of: 09/22/2026
MedScribeOverall
Test details
No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better
83.71 %
Winner86.534 %
Vals AI
Source details
Data as of: 09/22/2026
MysteryMechanismOverall
Test details
No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better
19.369 %
Winner30.631 %
Vals AI
Source details
Data as of: 09/22/2026
ProofBenchOverall
Test details
No documented difference in the test setupVersion: 1.1Metric: accuracyScoring: Higher is better
Winner64 %
51 %
Vals AI
Source details
Data as of: 09/22/2026
Public Benefits Bench v1.1Overall
Test details
No documented difference in the test setupVersion: 1.1Metric: accuracyScoring: Higher is better
57.645 %
Winner66.847 %
Vals AI
Source details
Data as of: 09/22/2026
SAGEOverall
Test details
No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better
Winner48.091 %
28.9 %
Vals AI
Source details
Data as of: 09/22/2026
Tax Agent BenchOverall
Test details
No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better
58.864 %
Winner70.788 %
Vals AI
Source details
Data as of: 09/22/2026
Terminal-Bench 2.1Overall
Test details
No documented difference in the test setupVersion: 2.1Metric: accuracyScoring: Higher is better
73.034 %
Winner78.277 %
Vals AI
Source details
Data as of: 09/22/2026
Vals IndexOverall
Test details
No documented difference in the test setupVersion: 2Metric: weighted index scoreScoring: Higher is better
58.45 %
Winner59.167 %
Vals AI
Source details
Data as of: 09/22/2026
Vibe Code Bench v1.1Overall
Test details
No documented difference in the test setupVersion: 1.1Metric: accuracyScoring: Higher is betterSettings: Harness: OpenHands
Winner81.649 %
76.239 %
Vals AI
Source details
Data as of: 09/22/2026

Key to the marks:better valuebetter, but not conclusivetie

Our model tests

Our tests

Compare how the models respond to the same prompt. Each test shows the first attempt, with no subsequent fixes to the generated code. These results do not contribute to an overall score.

Pelican on a bicycle

A community classic for free-form SVG drawing.

GPT-6 Luna

Not tested yet

Grok 4.6

API access was unavailable for this run. The model was not evaluated.

Reasoning (requested): high

First attempt
Run date
7 Sept 2026
API provider
openrouter
Requested API model
x-ai/grok-4.6
Reasoning setting
high
Pinned endpoint
xAI | x-ai/grok-4.6-20260810
Temperature
Provider default
Token limit including reasoning
8,192 tokens
Test protocol
community-visual-tests-v1
Technical checks
Not run

Not yet visually reviewed. A successful recording does not confirm correct physics or full compliance with the prompt.

Prompt and test conditions

Generate an SVG of a pelican riding a bicycle

Token limit including reasoning: 8,192 tokens

Task origin (Simon Willison)

How to read this comparison

Winning one benchmark is not an overall verdict

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

The standard price table uses direct developer rates. The provider comparison labels OpenRouter endpoints, regions, and special tariffs separately.

Every result links to its measurement source and retrieval date. Labels distinguish vendor reports, official benchmark leaderboards, and independent evaluations. Disputed or archived results are excluded.

More matchups

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