Noometry

Model comparison

Gemini 3.5 Flash vs gpt-oss-120b

Gemini 3.5 Flash is the stronger model overall, scoring 54.1 to 36.0 on the Noometry Index. gpt-oss-120b costs 48× less per token, which makes it the better buy when Gemini 3.5 Flash's lead doesn't matter for your workload.

Last verified . 32 shared benchmarks.

Gemini 3.5 Flash Google

54.1

Rank #29 Confirmed

gpt-oss-120b OpenAI

36.0

Rank #210 Confirmed

Summary

  • They share 32 benchmarks with published results for both. Gemini 3.5 Flash scores higher in 9 categories and gpt-oss-120b in 0 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Gemini 3.5 Flash leads 62.7 to 19.5.
  • The biggest single-benchmark swing is SimpleBench: 76.7% for Gemini 3.5 Flash and 22.1% for gpt-oss-120b.
  • gpt-oss-120b is cheaper at $0.037 / $0.17 per million input/output tokens, against $1.50 / $9 for Gemini 3.5 Flash.
  • Gemini 3.5 Flash accepts more context: 1.05M tokens versus 131K.
  • gpt-oss-120b has downloadable open weights; the other is API-only.

Side by side

Gemini 3.5 Flashgpt-oss-120b
ProviderGoogleOpenAI
Noometry Index54.136.0
Released2026-05-192025-08-05
WeightsProprietaryOpen
Context window1.05M131K
Max output66K41K
Input $ / M tokens$1.50$0.037
Output $ / M tokens$9$0.17
Results tracked5448

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Category by category

Coding Gemini 3.5 Flash leads

Gemini 3.5 Flash: 49.1 (#46), gpt-oss-120b: 33.2 (#251)

BenchmarkGemini 3.5 Flashgpt-oss-120b
SciCode53.1%36%
WeirdML62.6%48.2%
LMArena Coding14921380
ALE-Bench911.02575.62
SWE-bench Verified79.3%—
DeepSWE37.4%—
SWE-bench Verified (bash only)—26%
Aider Polyglot—41.8%
LMArena WebDev1499—
AlgoTune—1.41

Agentic & Tool Use Gemini 3.5 Flash leads

Gemini 3.5 Flash: 24.8 (#107), gpt-oss-120b: 12.1 (#145)

BenchmarkGemini 3.5 Flashgpt-oss-120b
APEX-Agents27.5%4.4%
Vending-Bench 25,396-21.53
Terminal-Bench—18.7%
GBAEval6.7%—
GDP.pdf14%—
METR Time Horizons—56.6%

Reasoning Gemini 3.5 Flash leads

Gemini 3.5 Flash: 62.7 (#16), gpt-oss-120b: 19.5 (#236)

BenchmarkGemini 3.5 Flashgpt-oss-120b
SimpleBench76.7%22.1%
CritPt13.1%1.1%
Chess Puzzles50%20%
LMArena Hard Prompts14881364
Mystery Game Puzzles32%2%
DTBench94.7%76.3%
LMCA47.1%22.1%
Surface Evolver Bench58.1%25%
Epoch Capabilities Index154.55139.94
ARC-AGI-272.1%—
Kagi LLM Benchmark—58.6%
NYT Connections (extended)92.6%—
ARC-AGI-192.5%—
EnigmaEval25.4%—
EBR-Bench4.8%—
ForecastBench59—

Math Gemini 3.5 Flash leads

Gemini 3.5 Flash: 60.5 (#30), gpt-oss-120b: 50.6 (#43)

BenchmarkGemini 3.5 Flashgpt-oss-120b
OTIS Mock AIME 2024-202595.6%88.9%
LMArena Math15021388
FrontierMath (Tiers 1-3)62.8%—
FrontierMath Tier 426.8%—
MathArena Final-Answer Competitions76.3%—
ProofBench31%—
Omni-MATH—68.8%
FrontierMath (Feb 2025 set)39%—
FrontierMath Tier 4 (v1)14.6%—

Knowledge Gemini 3.5 Flash leads

Gemini 3.5 Flash: 66.3 (#10), gpt-oss-120b: 42.3 (#89)

BenchmarkGemini 3.5 Flashgpt-oss-120b
GPQA Diamond92.8%75.8%
LMArena Expert14931356
SimpleQA Verified66.2%—
MMLU-Pro—79.5%
Confabulations—15.7%
Vectara Hallucination Rate—14.2%
GPQA (HELM)—68.4%

Multimodal Not comparable

Gemini 3.5 Flash: 45.7 (#13), gpt-oss-120b: —

BenchmarkGemini 3.5 Flashgpt-oss-120b
LMArena Vision1311—
Blueprint-Bench 233.6%—
LMArena Document1463—

Multilingual Gemini 3.5 Flash leads

Gemini 3.5 Flash: 57.1 (#12), gpt-oss-120b: 48.2 (#142)

BenchmarkGemini 3.5 Flashgpt-oss-120b
LMArena Non-English14751350
LMArena Chinese15251384
LMArena French14901370
LMArena German15001355
LMArena Japanese14811332
LMArena Korean14531283
LMArena Russian14911343
LMArena Spanish14781388

Instruction Following Gemini 3.5 Flash leads

Gemini 3.5 Flash: 77.2 (#29), gpt-oss-120b: 69.5 (#168)

BenchmarkGemini 3.5 Flashgpt-oss-120b
LMArena Instruction Following14661318
IFEval—83.6%

Long Context Gemini 3.5 Flash leads

Gemini 3.5 Flash: 45.3 (#39), gpt-oss-120b: 31.4 (#273)

BenchmarkGemini 3.5 Flashgpt-oss-120b
LMArena Longer Query14811319
Fiction.LiveBench—44.4%

Writing & Preference Gemini 3.5 Flash leads

Gemini 3.5 Flash: 65.5 (#46), gpt-oss-120b: 46.7 (#213)

BenchmarkGemini 3.5 Flashgpt-oss-120b
LMArena Text14811366
LMArena Creative Writing14671274
LMArena Multi-Turn14821340
Short-Story Creative Writing—77.1%
EQ-Bench Creative Writing—961
WildBench—84.5%
EQ-Bench 41087—

Frequently asked questions

Is Gemini 3.5 Flash better than gpt-oss-120b?

Gemini 3.5 Flash is the stronger model overall, scoring 54.1 to 36.0 on the Noometry Index. gpt-oss-120b costs 48× less per token, which makes it the better buy when Gemini 3.5 Flash's lead doesn't matter for your workload.

Which is cheaper, Gemini 3.5 Flash or gpt-oss-120b?

gpt-oss-120b is cheaper. It lists at $0.037 per million input tokens and $0.17 per million output tokens; Gemini 3.5 Flash lists at $1.50 and $9.

Is Gemini 3.5 Flash or gpt-oss-120b better for coding?

Gemini 3.5 Flash scores higher on coding benchmarks: 49.1 versus 33.2 in the Noometry coding category.

Which has the bigger context window?

Gemini 3.5 Flash does, with 1.05M tokens against 131K.

How many benchmarks do Gemini 3.5 Flash and gpt-oss-120b share?

32 benchmarks have published results for both models. Gemini 3.5 Flash has 54 scored results on Noometry and gpt-oss-120b has 48.

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