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Model comparison

GPT-5.6 Luna vs Inkling

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
0.4pts
winning →
Thinking Machines Lab
67.54/100
3 category wins2 category wins

Public leaderboard positions: GPT-5.6 Luna #22 (Estimated); Inkling #20 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. GPT-5.6 Luna and Inkling share 22 comparable benchmark results. 5 of 8 categories are comparable. 19 results are unique to GPT-5.6 Luna; 10 to Inkling.

Updated July 23, 2026
Shared results
22
GPT-5.6 Luna only
19
Inkling only
10
Comparable categories
5 / 8

Pick Inkling 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 stronger reasoning-first profile.

Confidence note. This is a partial-evidence comparison with 22 shared benchmark results across 5 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

Inkling has the cleaner BenchAlign overall profile here, landing at 67.54 versus 67.17. It is a real lead, but still close enough that category-level strengths matter more than the headline number.

Inkling's sharpest advantage is in mathematics, where it averages 97.1 against 73.6. The single biggest benchmark swing on the page is Terminal-Bench 2.0, 84.7% to 63.8%. GPT-5.6 Luna does hit back in knowledge, so the answer changes if that is the part of the workload you care about most.

GPT-5.6 Luna is also the more expensive model on tokens at $1.00 input / $6.00 output per 1M tokens, versus $1.87 input / $4.68 output per 1M tokens for Inkling. GPT-5.6 Luna is the reasoning model in the pair, while Inkling is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use.

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 Inkling
CategoryGPT-5.6 LunaΔInkling
KnowledgeGPT-5.6 Luna92.3Margin 40.7Inkling51.6
MathGPT-5.6 Luna73.6Margin 23.5Inkling97.1
AgenticGPT-5.6 Luna84.1Margin 14.7Inkling69.4
CodingGPT-5.6 Luna62.7Margin 5.9Inkling68.6
MultimodalGPT-5.6 Luna78.4Margin 1.9Inkling76.5
Inst. FollowingGPT-5.6 LunaNot measuredMarginNo overlapInkling79.8

Decisive benchmark drivers

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

More
A · GPT-5.6 LunaB · Inkling
  1. Terminal-Bench 2.0

    Agentic
    Source ↗
    A 84.7%B 63.8%
    Winner: GPT-5.6 LunaΔ 20.9
    Terminal-Bench 2.0: GPT-5.6 Luna scored 84.7%; Inkling scored 63.8%. GPT-5.6 Luna wins this benchmark.
  2. SWE-bench Pro

    Coding
    Source ↗
    A 62.7%B 54.3%
    Winner: GPT-5.6 LunaΔ 8.4
    SWE-bench Pro: GPT-5.6 Luna scored 62.7%; Inkling scored 54.3%. GPT-5.6 Luna wins this benchmark.
  3. BrowseComp

    Agentic
    Source ↗
    A 83.3%B 77.1%
    Winner: GPT-5.6 LunaΔ 6.2
    BrowseComp: GPT-5.6 Luna scored 83.3%; Inkling scored 77.1%. GPT-5.6 Luna wins this benchmark.
  4. MMMU-Pro

    Multimodal
    Source ↗
    A 78.4%B 73.5%
    Winner: GPT-5.6 LunaΔ 4.9
    MMMU-Pro: GPT-5.6 Luna scored 78.4%; Inkling scored 73.5%. GPT-5.6 Luna wins this benchmark.
  5. GPQA

    Knowledge
    Source ↗
    A 92.3%B 87.9%
    Winner: GPT-5.6 LunaΔ 4.4
    GPQA: GPT-5.6 Luna scored 92.3%; Inkling scored 87.9%. 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 LunaInklingComparison
Input / output priceUSD per 1M tokensGPT-5.6 Luna$1 input / $6 outputInkling$1.87 input / $4.68 outputInkling has the lower combined listed price.
Generation speedtokens per secondGPT-5.6 LunaNot availableInklingNot availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenGPT-5.6 LunaNot availableInklingNot availableA complete latency comparison is not available.
Context windowmaximum listed tokensGPT-5.6 Luna1MInkling1MListed context windows are equal.

Benchmark Deep Dive

AgenticGPT-5.6 Luna wins
BenchmarkGPT-5.6 LunaInklingResult
Terminal-Bench 2.0Source 84.7%63.8%GPT-5.6 Luna leads
BrowseCompSource 83.3%77.1%GPT-5.6 Luna leads
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%32.3%GPT-5.6 Luna leads
GDPval-AASource 54.2%36.9%GPT-5.6 Luna leads
GDPval-AASource 15841239GPT-5.6 Luna leads
AA Harvey LABSource 87.9%Not comparable
AA ITBenchSource 40.3%Not comparable
AA Tau3 BankingSource 27.2%23.7%GPT-5.6 Luna leads
AA AutomationBenchSource 42.2%Not comparable
aaTerminalBench21Source 80.9%Not comparable
APEX-Agents-AASource 35.8%Not comparable
MCP AtlasSource 74.1%Not comparable
Design Arena Agentic Web DevSource 1257Not comparable
AA BriefcaseSource 836Not comparable
CodingInkling wins
BenchmarkGPT-5.6 LunaInklingResult
SWE-bench ProSource 62.7%54.3%GPT-5.6 Luna leads
Terminal-Bench 2.0Source 84.7%63.8%GPT-5.6 Luna leads
deepSweSource 67.2%Not comparable
FrontierCode 1.1 ExtendedSource 55.1%Not comparable
cursorBench32Source 61.1%Not comparable
AA Coding IndexSource 71.5%52.1%GPT-5.6 Luna leads
AA-SciCodeSource 52.5%46.1%GPT-5.6 Luna leads
SWE-bench VerifiedSource 77.6%Not comparable
Reasoning
BenchmarkGPT-5.6 LunaInklingResult
ARC-AGI-3Source 0.2%Not comparable
AA-LCRSource 74.0%63.3%GPT-5.6 Luna leads
CritPtSource 20.6%5.4%GPT-5.6 Luna leads
KnowledgeGPT-5.6 Luna wins
BenchmarkGPT-5.6 LunaInklingResult
GPQASource 92.3%87.9%GPT-5.6 Luna leads
GPQA-DSource 92.3%87.9%GPT-5.6 Luna leads
HealthBench ProfessionalSource 55.7%Not comparable
HealthBench HardSource 32.0%Not comparable
Artificial Analysis Intelligence IndexSource 51.2%40.7%GPT-5.6 Luna leads
AA-GPQA DiamondSource 91.1%87.2%GPT-5.6 Luna leads
AA-HLESource 37.2%29.7%GPT-5.6 Luna leads
AA-Omniscience IndexSource -11.2%2.1%Inkling leads
AA-Omniscience AccuracySource 41.5%40.0%GPT-5.6 Luna leads
AA-Omniscience Hallucination RateSource 90.1%63.1%Inkling leads
HLESource 46%Not comparable
HLE w/o toolsSource 30%Not comparable
MathInkling wins
BenchmarkGPT-5.6 LunaInklingResult
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
AIME26Source 97.1%Not comparable
MultimodalGPT-5.6 Luna wins
BenchmarkGPT-5.6 LunaInklingResult
MMMU-ProSource 78.4%73.5%GPT-5.6 Luna leads
MMMU-Pro w/ PythonSource 79.5%Not comparable
AA-MMMU-ProSource 78.6%73.5%GPT-5.6 Luna leads
CharXivSource 82%Not comparable
CharXiv w/o toolsSource 78.1%Not comparable
Inst. Following
BenchmarkGPT-5.6 LunaInklingResult
IFBenchSource 79.8%Not comparable
Frequently Asked Questions (6)

Which is better, GPT-5.6 Luna or Inkling?

Inkling is ahead on BenchLM's BenchAlign leaderboard, 67.54 to 67.17. The biggest single separator in this matchup is Terminal-Bench 2.0, where the scores are 84.7% and 63.8%.

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

GPT-5.6 Luna has the edge for knowledge tasks in this comparison, averaging 92.3 versus 51.6. Inside this category, AA-Omniscience Hallucination Rate is the benchmark that creates the most daylight between them.

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

Inkling has the edge for coding in this comparison, averaging 68.6 versus 62.7. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.

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

Inkling has the edge for math in this comparison, averaging 97.1 versus 73.6. GPT-5.6 Luna stays close enough that the answer can still flip depending on your workload.

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

GPT-5.6 Luna has the edge for agentic tasks in this comparison, averaging 84.1 versus 69.4. Inside this category, GDPval-AA is the benchmark that creates the most daylight between them.

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

GPT-5.6 Luna has the edge for multimodal and grounded tasks in this comparison, averaging 78.4 versus 76.5. Inside this category, AA-MMMU-Pro is the benchmark that creates the most daylight between them.

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Last updated: July 23, 2026

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