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Model comparison

GPT-5.6 Luna vs Grok 4.5

Data verified

Head-to-head evidence from 22 shared benchmark results across 5 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

67.17/100
Margin
9.5pts
winning →
76.72/100
1 category wins1 category wins

Public leaderboard positions: GPT-5.6 Luna #22 (Estimated); Grok 4.5 #7 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. GPT-5.6 Luna and Grok 4.5 share 22 comparable benchmark results. 2 of 8 categories are comparable. 19 results are unique to GPT-5.6 Luna; 6 to Grok 4.5.

Updated July 23, 2026
Shared results
22
GPT-5.6 Luna only
19
Grok 4.5 only
6
Comparable categories
2 / 8

Pick Grok 4.5 if you want the stronger benchmark profile. GPT-5.6 Luna only becomes the better choice if agentic is the priority or you need the larger 1M context window.

Confidence note. This is a partial-evidence comparison with 22 shared benchmark results across 5 evidence categories; 2 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

Grok 4.5 is clearly ahead on the BenchAlign aggregate, 76.72 to 67.17. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Grok 4.5's sharpest advantage is in coding, where it averages 64.7 against 62.7. The single biggest benchmark swing on the page is SWE-bench Pro, 62.7% to 64.7%. GPT-5.6 Luna does hit back in agentic, so the answer changes if that is the part of the workload you care about most.

GPT-5.6 Luna gives you the larger context window at 1M, compared with 500K for Grok 4.5.

Category breakdown

Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.

Category scores and score margins for GPT-5.6 Luna and Grok 4.5
CategoryGPT-5.6 LunaΔGrok 4.5
CodingGPT-5.6 Luna62.7Margin→ 2.0Grok 4.564.7
AgenticGPT-5.6 Luna84.1Margin← 0.8Grok 4.583.3
KnowledgeGPT-5.6 Luna92.3MarginNo overlapGrok 4.5Not measured
MathGPT-5.6 Luna73.6MarginNo overlapGrok 4.5Not measured
MultimodalGPT-5.6 Luna78.4MarginNo overlapGrok 4.5Not measured

Decisive benchmark drivers

The largest measured benchmark gaps in this matchup, with exact reported values.

More
A · GPT-5.6 LunaB · Grok 4.5

  1. SWE-bench Pro

    Coding
    Source ↗
    A 62.7%B 64.7%
    Winner: Grok 4.5Δ 2
    SWE-bench Pro: GPT-5.6 Luna scored 62.7%; Grok 4.5 scored 64.7%. Grok 4.5 wins this benchmark.

  2. Terminal-Bench 2.0

    Agentic
    Source ↗
    A 84.7%B 83.3%
    Winner: GPT-5.6 LunaΔ 1.4
    Terminal-Bench 2.0: GPT-5.6 Luna scored 84.7%; Grok 4.5 scored 83.3%. GPT-5.6 Luna wins this benchmark.

Operational comparison

Runtime and commercial metrics are compared only when both models have a complete sourced value.

MetricGPT-5.6 LunaGrok 4.5Comparison
Input / output priceUSD per 1M tokensGPT-5.6 Luna$1 input / $6 outputGrok 4.5$2 input / $6 outputGPT-5.6 Luna has the lower combined listed price.
Generation speedtokens per secondGPT-5.6 LunaNot availableGrok 4.5Not availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenGPT-5.6 LunaNot availableGrok 4.5Not availableA complete latency comparison is not available.
Context windowmaximum listed tokensGPT-5.6 Luna1MGrok 4.5500KGPT-5.6 Luna lists the larger context window.

Benchmark Deep Dive

AgenticGPT-5.6 Luna wins
BenchmarkGPT-5.6 LunaGrok 4.5Result
Terminal-Bench 2.0Source 84.7%83.3%GPT-5.6 Luna leads
BrowseCompSource 83.3%—Not comparable
OSWorld 2.0Source 45.6%—Not comparable
CyberGymSource 77.9%—Not comparable
ExploitGymSource 12.4%—Not comparable
ToolathlonSource 53.4%—Not comparable
AA Agentic IndexSource 45.6%45.7%Grok 4.5 leads
GDPval-AASource 54.2%51.7%GPT-5.6 Luna leads
GDPval-AASource 15841535GPT-5.6 Luna leads
AA Harvey LABSource 87.9%92.4%Grok 4.5 leads
AA ITBenchSource 40.3%—Not comparable
AA Tau3 BankingSource 27.2%32.6%Grok 4.5 leads
AA AutomationBenchSource 42.2%51.4%Grok 4.5 leads
aaTerminalBench21Source 80.9%81.6%Grok 4.5 leads
APEX-Agents-AASource 35.8%—Not comparable
deepSweSource —53%Not comparable
AA BriefcaseSource —1323Not comparable
AA EnterpriseOps-GymSource —40.8%Not comparable
CodingGrok 4.5 wins
BenchmarkGPT-5.6 LunaGrok 4.5Result
SWE-bench ProSource 62.7%64.7%Grok 4.5 leads
Terminal-Bench 2.0Source 84.7%83.3%GPT-5.6 Luna leads
deepSweSource 67.2%—Not comparable
FrontierCode 1.1 ExtendedSource 55.1%—Not comparable
cursorBench32Source 61.1%66.7%Grok 4.5 leads
AA Coding IndexSource 71.5%72.5%Grok 4.5 leads
AA-SciCodeSource 52.5%54.1%Grok 4.5 leads
SWE MultilingualSource —78%Not comparable
VulcanBench v3Source —91.3%Not comparable
Reasoning
BenchmarkGPT-5.6 LunaGrok 4.5Result
ARC-AGI-3Source 0.2%—Not comparable
AA-LCRSource 74.0%67.7%GPT-5.6 Luna leads
CritPtSource 20.6%15.4%GPT-5.6 Luna leads
Knowledge
BenchmarkGPT-5.6 LunaGrok 4.5Result
GPQASource 92.3%—Not comparable
GPQA-DSource 92.3%—Not comparable
HealthBench ProfessionalSource 55.7%—Not comparable
HealthBench HardSource 32.0%—Not comparable
Artificial Analysis Intelligence IndexSource 51.2%53.8%Grok 4.5 leads
AA-GPQA DiamondSource 91.1%93.1%Grok 4.5 leads
AA-HLESource 37.2%40.3%Grok 4.5 leads
AA-Omniscience IndexSource -11.2%26.4%Grok 4.5 leads
AA-Omniscience AccuracySource 41.5%52.1%Grok 4.5 leads
AA-Omniscience Hallucination RateSource 90.1%53.5%Grok 4.5 leads
Math
BenchmarkGPT-5.6 LunaGrok 4.5Result
FrontierMath (legacy)Source 78.6%—Not comparable
FrontierMath v2 (Tiers 1-3)Source 78.600%—Not comparable
FrontierMath v2 (Tier 4)Source 58.500%—Not comparable
Multimodal
BenchmarkGPT-5.6 LunaGrok 4.5Result
MMMU-ProSource 78.4%—Not comparable
MMMU-Pro w/ PythonSource 79.5%—Not comparable
AA-MMMU-ProSource 78.6%80.4%Grok 4.5 leads
Design Arena WebsiteSource —1325Not comparable
Frequently Asked Questions (3)

Which is better, GPT-5.6 Luna or Grok 4.5?

Grok 4.5 is ahead on BenchLM's BenchAlign leaderboard, 76.72 to 67.17. The biggest single separator in this matchup is SWE-bench Pro, where the scores are 62.7% and 64.7%.

Which is better for coding, GPT-5.6 Luna or Grok 4.5?

Grok 4.5 has the edge for coding in this comparison, averaging 64.7 versus 62.7. Inside this category, cursorBench32 is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, GPT-5.6 Luna or Grok 4.5?

GPT-5.6 Luna has the edge for agentic tasks in this comparison, averaging 84.1 versus 83.3. Inside this category, GDPval-AA is the benchmark that creates the most daylight between them.

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