Model comparison

GPT-6.1 Sol vs GPT-6 Luna

GPT-6.1 Sol is the stronger model overall, scoring 65.6 to 53.3 on the Noometry Index. GPT-6 Luna costs 20× less per token, which makes it the better buy when GPT-6.1 Sol's lead doesn't matter for your workload.

Last verified . 33 shared benchmarks.

GPT-6.1 Sol OpenAI

65.6

Rank #6 Confirmed

GPT-6 Luna OpenAI

53.3

Rank #36 Confirmed

Summary

  • They share 33 benchmarks with published results for both. GPT-6.1 Sol scores higher in 10 categories and GPT-6 Luna in 0 categories; 10 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where GPT-6.1 Sol leads 81.9 to 48.2.
  • The biggest single-benchmark swing is Mystery Game Puzzles: 80% for GPT-6.1 Sol and 7% for GPT-6 Luna.
  • GPT-6 Luna is cheaper at $0.10 / $0.50 per million input/output tokens, against $2 / $10 for GPT-6.1 Sol.

Side by side

GPT-6.1 Sol and GPT-6 Luna specifications
GPT-6.1 SolGPT-6 Luna
ProviderOpenAIOpenAI
Noometry Index65.653.3
Released2026-09-292026-09-22
WeightsProprietaryProprietary
Context window1.05M1.05M
Max output128K128K
Input $ / M tokens$2$0.10
Output $ / M tokens$10$0.50
Results tracked3442

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Category by category

Coding GPT-6.1 Sol leads

GPT-6.1 Sol: 63.2 (#8), GPT-6 Luna: 55.5 (#25)

Coding benchmarks
BenchmarkGPT-6.1 SolGPT-6 Luna
DeepSWE75.2%66.6%
FrontierCode50.2%42.4%
LMArena WebDev17551581
SciCode55.8%54.6%
LMArena Coding14871439
ALE-Bench—1,577

Agentic & Tool Use GPT-6.1 Sol leads

GPT-6.1 Sol: 39.6 (#26), GPT-6 Luna: 33.3 (#54)

Agentic & Tool Use benchmarks
BenchmarkGPT-6.1 SolGPT-6 Luna
APEX-Agents60%44.3%
GDP.pdf32%23%

Reasoning GPT-6.1 Sol leads

GPT-6.1 Sol: 81.9 (#2), GPT-6 Luna: 48.2 (#41)

Reasoning benchmarks
BenchmarkGPT-6.1 SolGPT-6 Luna
ARC-AGI-294.2%59.3%
NYT Connections (extended)95.5%68.7%
ARC-AGI-198.5%86.7%
CritPt31.7%19.4%
Chess Puzzles61%31%
LMArena Hard Prompts14661411
Mystery Game Puzzles80%7%
Epoch Capabilities Index166.09156.28
EBR-Bench54.3%—
DTBench—90.1%
LMCA—44.5%

Math GPT-6.1 Sol leads

GPT-6.1 Sol: 93.7 (#1), GPT-6 Luna: 76.1 (#15)

Math benchmarks
BenchmarkGPT-6.1 SolGPT-6 Luna
FrontierMath (Tiers 1-3)93.7%78.9%
FrontierMath Tier 4100%56.1%
OTIS Mock AIME 2024-2025100%98.9%
ProofBench99%64%
LMArena Math14641416

Knowledge GPT-6.1 Sol leads

GPT-6.1 Sol: 71.8 (#4), GPT-6 Luna: 57.0 (#41)

Knowledge benchmarks
BenchmarkGPT-6.1 SolGPT-6 Luna
GPQA Diamond95.4%90.5%
SimpleQA Verified73.9%41.4%
LMArena Expert15021444

Multimodal GPT-6.1 Sol leads

GPT-6.1 Sol: 52.7 (#5), GPT-6 Luna: 42.4 (#30)

Multimodal benchmarks
BenchmarkGPT-6.1 SolGPT-6 Luna
LMArena Vision12881217
Furniture Assembly80%44.2%
Blueprint-Bench 2—31.2%

Multilingual GPT-6.1 Sol leads

GPT-6.1 Sol: 54.3 (#46), GPT-6 Luna: 50.5 (#117)

Multilingual benchmarks
BenchmarkGPT-6.1 SolGPT-6 Luna
LMArena Non-English14381386
LMArena Chinese14771433
LMArena Russian14551394
LMArena French—1420
LMArena German—1369
LMArena Japanese—1369
LMArena Korean—1360
LMArena Spanish—1393

Instruction Following GPT-6.1 Sol leads

GPT-6.1 Sol: 77.0 (#29), GPT-6 Luna: 74.3 (#99)

Instruction Following benchmarks
BenchmarkGPT-6.1 SolGPT-6 Luna
LMArena Instruction Following14681409

Long Context GPT-6.1 Sol leads

GPT-6.1 Sol: 44.9 (#54), GPT-6 Luna: 43.0 (#111)

Long Context benchmarks
BenchmarkGPT-6.1 SolGPT-6 Luna
LMArena Longer Query14651409

Writing & Preference GPT-6.1 Sol leads

GPT-6.1 Sol: 63.6 (#63), GPT-6 Luna: 58.3 (#119)

Writing & Preference benchmarks
BenchmarkGPT-6.1 SolGPT-6 Luna
LMArena Text14471391
LMArena Creative Writing14321363
LMArena Multi-Turn14491396

Frequently asked questions

Is GPT-6.1 Sol better than GPT-6 Luna?

GPT-6.1 Sol is the stronger model overall, scoring 65.6 to 53.3 on the Noometry Index. GPT-6 Luna costs 20× less per token, which makes it the better buy when GPT-6.1 Sol's lead doesn't matter for your workload.

Which is cheaper, GPT-6.1 Sol or GPT-6 Luna?

GPT-6 Luna is cheaper. It lists at $0.10 per million input tokens and $0.50 per million output tokens; GPT-6.1 Sol lists at $2 and $10.

Is GPT-6.1 Sol or GPT-6 Luna better for coding?

GPT-6.1 Sol scores higher on coding benchmarks: 63.2 versus 55.5 in the Noometry coding category.

Which has the bigger context window?

Both accept 1.05M tokens.

How many benchmarks do GPT-6.1 Sol and GPT-6 Luna share?

33 benchmarks have published results for both models. GPT-6.1 Sol has 34 scored results on Noometry and GPT-6 Luna has 42.

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