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Model comparison

GPT-5.4 vs GPT-5.6 Luna

Data verified

Head-to-head evidence from 29 shared benchmark results across 6 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

OpenAI
74.24/100
Margin
7.1pts
← winning
67.17/100
0 category wins5 category wins

Public leaderboard positions: GPT-5.4 #8 (Supported); GPT-5.6 Luna #22 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. GPT-5.4 and GPT-5.6 Luna share 29 comparable benchmark results. 5 of 8 categories are comparable. 23 results are unique to GPT-5.4; 12 to GPT-5.6 Luna.

Updated July 23, 2026
Shared results
29
GPT-5.4 only
23
GPT-5.6 Luna only
12
Comparable categories
5 / 8

Pick GPT-5.4 if you want the stronger benchmark profile. GPT-5.6 Luna only becomes the better choice if knowledge is the priority or you want the cheaper token bill.

Confidence note. This is a partial-evidence comparison with 29 shared benchmark results across 6 evidence categories; 5 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

GPT-5.4 is clearly ahead on the BenchAlign aggregate, 74.24 to 67.17. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

GPT-5.4 is also the more expensive model on tokens at $2.50 input / $15.00 output per 1M tokens, versus $1.00 input / $6.00 output per 1M tokens for GPT-5.6 Luna. That is roughly 2.5x on output cost alone. GPT-5.4 gives you the larger context window at 1.05M, compared with 1M for GPT-5.6 Luna.

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-5.4 and GPT-5.6 Luna
CategoryGPT-5.4ΔGPT-5.6 Luna
KnowledgeGPT-5.457.6Margin 34.7GPT-5.6 Luna92.3
MathGPT-5.442.5Margin 31.1GPT-5.6 Luna73.6
AgenticGPT-5.477.2Margin 6.9GPT-5.6 Luna84.1
MultimodalGPT-5.473.2Margin 5.2GPT-5.6 Luna78.4
CodingGPT-5.457.7Margin 5.0GPT-5.6 Luna62.7

Decisive benchmark drivers

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

More
A · GPT-5.4B · GPT-5.6 Luna
  1. FrontierMath v2 (Tier 4)

    Math
    Source ↗
    A 27.100%B 58.500%
    Winner: GPT-5.6 LunaΔ 31.4
    FrontierMath v2 (Tier 4): GPT-5.4 scored 27.100%; GPT-5.6 Luna scored 58.500%. GPT-5.6 Luna wins this benchmark.
  2. FrontierMath v2 (Tiers 1-3)

    Math
    Source ↗
    A 47.600%B 78.600%
    Winner: GPT-5.6 LunaΔ 31
    FrontierMath v2 (Tiers 1-3): GPT-5.4 scored 47.600%; GPT-5.6 Luna scored 78.600%. GPT-5.6 Luna wins this benchmark.
  3. Terminal-Bench 2.0

    Agentic
    Source ↗
    A 75.1%B 84.7%
    Winner: GPT-5.6 LunaΔ 9.6
    Terminal-Bench 2.0: GPT-5.4 scored 75.1%; GPT-5.6 Luna scored 84.7%. GPT-5.6 Luna wins this benchmark.
  4. SWE-bench Pro

    Coding
    Source ↗
    A 57.7%B 62.7%
    Winner: GPT-5.6 LunaΔ 5
    SWE-bench Pro: GPT-5.4 scored 57.7%; GPT-5.6 Luna scored 62.7%. GPT-5.6 Luna wins this benchmark.
  5. MMMU-Pro

    Multimodal
    Source ↗
    A 81.2%B 78.4%
    Winner: GPT-5.4Δ 2.8
    MMMU-Pro: GPT-5.4 scored 81.2%; GPT-5.6 Luna scored 78.4%. GPT-5.4 wins this benchmark.

Operational comparison

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

MetricGPT-5.4GPT-5.6 LunaComparison
Input / output priceUSD per 1M tokensGPT-5.4$2.5 input / $15 outputGPT-5.6 Luna$1 input / $6 outputGPT-5.6 Luna has the lower combined listed price.
Generation speedtokens per secondGPT-5.474 tok/sGPT-5.6 LunaNot availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenGPT-5.4151.79 sGPT-5.6 LunaNot availableA complete latency comparison is not available.
Context windowmaximum listed tokensGPT-5.41.05MGPT-5.6 Luna1MGPT-5.4 lists the larger context window.

Benchmark Deep Dive

AgenticGPT-5.6 Luna wins
BenchmarkGPT-5.4GPT-5.6 LunaResult
Terminal-Bench 2.0Source 75.1%84.7%GPT-5.6 Luna leads
CyberGymSource 79.0%77.9%GPT-5.4 leads
BrowseCompSource 82.7%83.3%GPT-5.6 Luna leads
OSWorld-VerifiedSource 75%Not comparable
MCP AtlasSource 70.6%Not comparable
ToolathlonSource 54.6%53.4%GPT-5.4 leads
τ²-bench resultsSource 87.1%Not comparable
Claw-EvalSource 60.3%Not comparable
DeepSearchQASource 73.6%Not comparable
AA Agentic IndexSource 41.1%45.6%GPT-5.6 Luna leads
APEX-Agents-AASource 33.3%35.8%GPT-5.6 Luna leads
GDPval-AASource 44.7%54.2%GPT-5.6 Luna leads
GDPval-AASource 13951584GPT-5.6 Luna leads
Gert LabsSource 64.89%Not comparable
ResearchClawBenchSource 15.3%Not comparable
JobBenchSource 38.9%Not comparable
ExploitGymSource 6.0%12.4%GPT-5.6 Luna leads
OSWorld 2.0Source 45.6%Not comparable
AA Harvey LABSource 87.9%Not comparable
AA ITBenchSource 40.3%Not comparable
AA Tau3 BankingSource 27.2%Not comparable
AA AutomationBenchSource 42.2%Not comparable
aaTerminalBench21Source 80.9%Not comparable
CodingGPT-5.6 Luna wins
BenchmarkGPT-5.4GPT-5.6 LunaResult
LiveCodeBench ProSource 87.5%Not comparable
SWE-bench ProSource 57.7%62.7%GPT-5.6 Luna leads
React Native EvalsSource 85.3%Not comparable
Vibe Code BenchSource 67.42%Not comparable
AA Coding IndexSource 71.0%71.5%GPT-5.6 Luna leads
AA-SciCodeSource 56.6%52.5%GPT-5.4 leads
Terminal-Bench 2.0Source 84.7%Not comparable
deepSweSource 67.2%Not comparable
FrontierCode 1.1 ExtendedSource 55.1%Not comparable
cursorBench32Source 61.1%Not comparable
Reasoning
BenchmarkGPT-5.4GPT-5.6 LunaResult
AA-LCRSource 74.0%74.0%Tie
CritPtSource 23.4%20.6%GPT-5.4 leads
ARC-AGI-3Source 0.2%Not comparable
KnowledgeGPT-5.6 Luna wins
BenchmarkGPT-5.4GPT-5.6 LunaResult
GPQASource 92.8%92.3%GPT-5.4 leads
HLESource 52.1%Not comparable
HLE w/o toolsSource 39.8%Not comparable
GPQA-DSource 92.8%92.3%GPT-5.4 leads
HealthBench HardSource 40.1%32.0%GPT-5.4 leads
MedXpertQA (Text)Source 59.6%Not comparable
Artificial Analysis Intelligence IndexSource 51.4%51.2%GPT-5.4 leads
AA-GPQA DiamondSource 92.0%91.1%GPT-5.4 leads
AA-HLESource 41.6%37.2%GPT-5.4 leads
AA-Omniscience IndexSource 5.7%-11.2%GPT-5.4 leads
AA-Omniscience AccuracySource 50.0%41.5%GPT-5.4 leads
AA-Omniscience Hallucination RateSource 88.6%90.1%GPT-5.4 leads
HealthBench ProfessionalSource 48.1%55.7%GPT-5.6 Luna leads
MathGPT-5.6 Luna wins
BenchmarkGPT-5.4GPT-5.6 LunaResult
FrontierMath v2 (Tiers 1-3)Source 47.600%78.600%GPT-5.6 Luna leads
FrontierMath v2 (Tier 4)Source 27.100%58.500%GPT-5.6 Luna leads
FrontierMath (legacy)Source 78.6%Not comparable
MultimodalGPT-5.6 Luna wins
BenchmarkGPT-5.4GPT-5.6 LunaResult
MMMU-ProSource 81.2%78.4%GPT-5.4 leads
OfficeQA ProSource 53.2%Not comparable
MMMU-Pro w/ PythonSource 82.1%79.5%GPT-5.4 leads
CharXivSource 82.8%Not comparable
ERQASource 65.4%Not comparable
SimpleVQASource 61.1%Not comparable
ScreenSpot ProSource 85.4%Not comparable
ZeroBenchSource 41.0%Not comparable
MedXpertQA (MM)Source 77.1%Not comparable
AA-MMMU-ProSource 78.4%78.6%GPT-5.6 Luna leads
Design Arena WebsiteSource 1250Not comparable
Inst. Following
BenchmarkGPT-5.4GPT-5.6 LunaResult
AA-IFBenchSource 73.9%Not comparable
Frequently Asked Questions (6)

Which is better, GPT-5.4 or GPT-5.6 Luna?

GPT-5.4 is ahead on BenchLM's BenchAlign leaderboard, 74.24 to 67.17. The biggest single separator in this matchup is FrontierMath v2 (Tier 4), where the scores are 27.100% and 58.500%.

Which is better for knowledge tasks, GPT-5.4 or GPT-5.6 Luna?

GPT-5.6 Luna has the edge for knowledge tasks in this comparison, averaging 92.3 versus 57.6. Inside this category, AA-Omniscience Index is the benchmark that creates the most daylight between them.

Which is better for coding, GPT-5.4 or GPT-5.6 Luna?

GPT-5.6 Luna has the edge for coding in this comparison, averaging 62.7 versus 57.7. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.

Which is better for math, GPT-5.4 or GPT-5.6 Luna?

GPT-5.6 Luna has the edge for math in this comparison, averaging 73.6 versus 42.5. Inside this category, FrontierMath v2 (Tier 4) is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, GPT-5.4 or GPT-5.6 Luna?

GPT-5.6 Luna has the edge for agentic tasks in this comparison, averaging 84.1 versus 77.2. Inside this category, GDPval-AA is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, GPT-5.4 or GPT-5.6 Luna?

GPT-5.6 Luna has the edge for multimodal and grounded tasks in this comparison, averaging 78.4 versus 73.2. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.

Related Comparisons

Last updated: July 23, 2026

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