Model comparison

GPT-6 Sol vs gpt-oss-20b

GPT-6 Sol is the stronger model overall, scoring 61.8 to 32.5 on the Noometry Index. gpt-oss-20b costs 111× less per token, which makes it the better buy when GPT-6 Sol's lead doesn't matter for your workload.

Last verified . 25 shared benchmarks.

GPT-6 Sol OpenAI

61.8

Rank #12 Confirmed

gpt-oss-20b OpenAI

32.5

Rank #255 Confirmed

Summary

  • They share 25 benchmarks with published results for both. GPT-6 Sol scores higher in 9 categories and gpt-oss-20b in 0 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where GPT-6 Sol leads 74.0 to 19.3.
  • The biggest single-benchmark swing is LMCA: 59.1% for GPT-6 Sol and 14.5% for gpt-oss-20b.
  • gpt-oss-20b is cheaper at $0.018 / $0.09 per million input/output tokens, against $2 / $10 for GPT-6 Sol.
  • GPT-6 Sol accepts more context: 1.05M tokens versus 131K.
  • gpt-oss-20b has downloadable open weights; the other is API-only.

Side by side

GPT-6 Sol and gpt-oss-20b specifications
GPT-6 Solgpt-oss-20b
ProviderOpenAIOpenAI
Noometry Index61.832.5
Released2026-09-222025-08-05
WeightsProprietaryOpen
Context window1.05M131K
Max output128K16K
Input $ / M tokens$2$0.018
Output $ / M tokens$10$0.09
Results tracked4534

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Category by category

Coding GPT-6 Sol leads

GPT-6 Sol: 60.1 (#11), gpt-oss-20b: 37.6 (#192)

Coding benchmarks
BenchmarkGPT-6 Solgpt-oss-20b
SciCode57.6%34.4%
LMArena Coding14471306
ALE-Bench2,462566.05
DeepSWE68.8%—
FrontierCode49.3%—
LMArena WebDev1688—
WeirdML—40.9%

Agentic & Tool Use GPT-6 Sol leads

GPT-6 Sol: 37.2 (#36), gpt-oss-20b: 9.3 (#154)

Agentic & Tool Use benchmarks
BenchmarkGPT-6 Solgpt-oss-20b
Terminal-Bench—3.4%
APEX-Agents54.3%—
GDP.pdf26.4%—
Vending-Bench 214,428—

Reasoning GPT-6 Sol leads

GPT-6 Sol: 74.0 (#9), gpt-oss-20b: 19.3 (#261)

Reasoning benchmarks
BenchmarkGPT-6 Solgpt-oss-20b
CritPt30.9%1.4%
LMArena Hard Prompts14181274
DTBench97.3%68%
LMCA59.1%14.5%
Epoch Capabilities Index162.72137.82
ARC-AGI-289.6%—
Kagi LLM Benchmark—53.2%
NYT Connections (extended)90.1%—
ARC-AGI-195.5%—
Chess Puzzles—4%
EBR-Bench53.3%—
Mystery Game Puzzles56%—

Math GPT-6 Sol leads

GPT-6 Sol: 87.2 (#7), gpt-oss-20b: 39.4 (#103)

Math benchmarks
BenchmarkGPT-6 Solgpt-oss-20b
OTIS Mock AIME 2024-2025100%65.3%
LMArena Math14021317
FrontierMath (Tiers 1-3)89.8%—
FrontierMath Tier 490%—
ProofBench83%—
Omni-MATH—56.5%

Knowledge GPT-6 Sol leads

GPT-6 Sol: 64.8 (#15), gpt-oss-20b: 34.6 (#195)

Knowledge benchmarks
BenchmarkGPT-6 Solgpt-oss-20b
GPQA Diamond94.3%60.8%
LMArena Expert14391258
SimpleQA Verified60.7%—
MMLU-Pro—74%
Vectara Hallucination Rate6.5%—
GPQA (HELM)—59.4%

Multimodal Not comparable

GPT-6 Sol: 47.6 (#10), gpt-oss-20b: —

Multimodal benchmarks
BenchmarkGPT-6 Solgpt-oss-20b
LMArena Vision1245—
Blueprint-Bench 236.9%—
Furniture Assembly58.3%—

Multilingual GPT-6 Sol leads

GPT-6 Sol: 50.5 (#118), gpt-oss-20b: 42.2 (#197)

Multilingual benchmarks
BenchmarkGPT-6 Solgpt-oss-20b
LMArena Non-English13851268
LMArena Chinese14051314
LMArena German13901255
LMArena Japanese13851244
LMArena Korean13411236
LMArena Russian14011278
LMArena Spanish13841267
LMArena French1410—

Instruction Following GPT-6 Sol leads

GPT-6 Sol: 74.5 (#94), gpt-oss-20b: 61.8 (#240)

Instruction Following benchmarks
BenchmarkGPT-6 Solgpt-oss-20b
LMArena Instruction Following14121236
IFEval—73.2%

Long Context GPT-6 Sol leads

GPT-6 Sol: 43.1 (#108), gpt-oss-20b: 37.9 (#209)

Long Context benchmarks
BenchmarkGPT-6 Solgpt-oss-20b
LMArena Longer Query14111250

Writing & Preference GPT-6 Sol leads

GPT-6 Sol: 71.9 (#18), gpt-oss-20b: 35.5 (#265)

Writing & Preference benchmarks
BenchmarkGPT-6 Solgpt-oss-20b
LMArena Text13951287
LMArena Creative Writing13781201
EQ-Bench Creative Writing2125666
LMArena Multi-Turn14121268
WildBench—73.7%

Frequently asked questions

Is GPT-6 Sol better than gpt-oss-20b?

GPT-6 Sol is the stronger model overall, scoring 61.8 to 32.5 on the Noometry Index. gpt-oss-20b costs 111× less per token, which makes it the better buy when GPT-6 Sol's lead doesn't matter for your workload.

Which is cheaper, GPT-6 Sol or gpt-oss-20b?

gpt-oss-20b is cheaper. It lists at $0.018 per million input tokens and $0.09 per million output tokens; GPT-6 Sol lists at $2 and $10.

Is GPT-6 Sol or gpt-oss-20b better for coding?

GPT-6 Sol scores higher on coding benchmarks: 60.1 versus 37.6 in the Noometry coding category.

Which has the bigger context window?

GPT-6 Sol does, with 1.05M tokens against 131K.

How many benchmarks do GPT-6 Sol and gpt-oss-20b share?

25 benchmarks have published results for both models. GPT-6 Sol has 45 scored results on Noometry and gpt-oss-20b has 34.

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