Model comparison

GPT-5 Nano vs GPT-6.1 Sol

GPT-6.1 Sol is the stronger model overall, scoring 65.6 to 33.5 on the Noometry Index. GPT-5 Nano costs 29× less per token, which makes it the better buy when GPT-6.1 Sol's lead doesn't matter for your workload.

Last verified . 24 shared benchmarks.

GPT-5 Nano OpenAI

33.5

Rank #241 Confirmed

GPT-6.1 Sol OpenAI

65.6

Rank #6 Confirmed

Summary

  • They share 24 benchmarks with published results for both. GPT-5 Nano scores higher in 0 categories and GPT-6.1 Sol in 10 categories; 10 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where GPT-6.1 Sol leads 81.9 to 16.3.
  • The biggest single-benchmark swing is FrontierMath Tier 4: 2.4% for GPT-5 Nano and 100% for GPT-6.1 Sol.
  • GPT-5 Nano is cheaper at $0.05 / $0.40 per million input/output tokens, against $2 / $10 for GPT-6.1 Sol.
  • GPT-6.1 Sol accepts more context: 1.05M tokens versus 400K.

Side by side

GPT-5 Nano and GPT-6.1 Sol specifications
GPT-5 NanoGPT-6.1 Sol
ProviderOpenAIOpenAI
Noometry Index33.565.6
Released2025-08-072026-09-29
WeightsProprietaryProprietary
Context window400K1.05M
Max output128K128K
Input $ / M tokens$0.05$2
Output $ / M tokens$0.40$10
Results tracked4934

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Category by category

Coding GPT-6.1 Sol leads

GPT-5 Nano: 33.6 (#254), GPT-6.1 Sol: 63.2 (#8)

Coding benchmarks
BenchmarkGPT-5 NanoGPT-6.1 Sol
LMArena Coding13511487
DeepSWE—75.2%
FrontierCode—50.2%
SWE-bench Verified (bash only)34.8%—
LMArena WebDev—1755
SciCode—55.8%
WeirdML38.1%—
ALE-Bench718.67—

Agentic & Tool Use GPT-6.1 Sol leads

GPT-5 Nano: 25.8 (#106), GPT-6.1 Sol: 39.6 (#26)

Agentic & Tool Use benchmarks
BenchmarkGPT-5 NanoGPT-6.1 Sol
Terminal-Bench21.8%—
APEX-Agents—60%
Berkeley Function Calling Leaderboard51.5%—
GDP.pdf—32%

Reasoning GPT-6.1 Sol leads

GPT-5 Nano: 16.3 (#306), GPT-6.1 Sol: 81.9 (#2)

Reasoning benchmarks
BenchmarkGPT-5 NanoGPT-6.1 Sol
ARC-AGI-22.6%94.2%
ARC-AGI-120.7%98.5%
Chess Puzzles27%61%
LMArena Hard Prompts13281466
Mystery Game Puzzles9%80%
Epoch Capabilities Index139.38166.09
Kagi LLM Benchmark62.2%—
NYT Connections (extended)—95.5%
CritPt—31.7%
EBR-Bench—54.3%
DTBench62.7%—
LMCA7.9%—
ForecastBench59.1—

Math GPT-6.1 Sol leads

GPT-5 Nano: 29.4 (#241), GPT-6.1 Sol: 93.7 (#1)

Math benchmarks
BenchmarkGPT-5 NanoGPT-6.1 Sol
FrontierMath (Tiers 1-3)20%93.7%
FrontierMath Tier 42.4%100%
OTIS Mock AIME 2024-202581.1%100%
ProofBench12%99%
LMArena Math13171464
Omni-MATH54.6%—
MATH Level 595.2%—
FrontierMath (Feb 2025 set)8.3%—
FrontierMath Tier 4 (v1)2.1%—

Knowledge GPT-6.1 Sol leads

GPT-5 Nano: 35.9 (#178), GPT-6.1 Sol: 71.8 (#4)

Knowledge benchmarks
BenchmarkGPT-5 NanoGPT-6.1 Sol
GPQA Diamond69.4%95.4%
SimpleQA Verified11.7%73.9%
LMArena Expert13211502
MMLU-Pro77.8%—
Vectara Hallucination Rate10.5%—
GPQA (HELM)67.9%—

Multimodal GPT-6.1 Sol leads

GPT-5 Nano: 31.3 (#108), GPT-6.1 Sol: 52.7 (#5)

Multimodal benchmarks
BenchmarkGPT-5 NanoGPT-6.1 Sol
LMArena Vision11591288
VPCT37.2%—
Furniture Assembly—80%

Multilingual GPT-6.1 Sol leads

GPT-5 Nano: 45.3 (#172), GPT-6.1 Sol: 54.3 (#46)

Multilingual benchmarks
BenchmarkGPT-5 NanoGPT-6.1 Sol
LMArena Non-English13131438
LMArena Chinese13561477
LMArena Russian12961455
LMArena German1327—
LMArena Japanese1226—
LMArena Korean1269—
LMArena Spanish1360—

Instruction Following GPT-6.1 Sol leads

GPT-5 Nano: 75.0 (#79), GPT-6.1 Sol: 77.0 (#29)

Instruction Following benchmarks
BenchmarkGPT-5 NanoGPT-6.1 Sol
LMArena Instruction Following13061468
IFEval93.2%—

Long Context GPT-6.1 Sol leads

GPT-5 Nano: 31.3 (#281), GPT-6.1 Sol: 44.9 (#54)

Long Context benchmarks
BenchmarkGPT-5 NanoGPT-6.1 Sol
LMArena Longer Query13121465
Fiction.LiveBench44.4%—

Writing & Preference GPT-6.1 Sol leads

GPT-5 Nano: 39.1 (#249), GPT-6.1 Sol: 63.6 (#63)

Writing & Preference benchmarks
BenchmarkGPT-5 NanoGPT-6.1 Sol
LMArena Text13201447
LMArena Creative Writing12491432
LMArena Multi-Turn13111449
EQ-Bench Creative Writing705—
WildBench80.6%—

Frequently asked questions

Is GPT-5 Nano better than GPT-6.1 Sol?

GPT-6.1 Sol is the stronger model overall, scoring 65.6 to 33.5 on the Noometry Index. GPT-5 Nano costs 29× 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-5 Nano or GPT-6.1 Sol?

GPT-5 Nano is cheaper. It lists at $0.05 per million input tokens and $0.40 per million output tokens; GPT-6.1 Sol lists at $2 and $10.

Is GPT-5 Nano or GPT-6.1 Sol better for coding?

GPT-6.1 Sol scores higher on coding benchmarks: 63.2 versus 33.6 in the Noometry coding category.

Which has the bigger context window?

GPT-6.1 Sol does, with 1.05M tokens against 400K.

How many benchmarks do GPT-5 Nano and GPT-6.1 Sol share?

24 benchmarks have published results for both models. GPT-5 Nano has 49 scored results on Noometry and GPT-6.1 Sol has 34.

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