Model comparison

Gemini 3.8 Flash vs gpt-oss-20b

Gemini 3.8 Flash is the stronger model overall, scoring 61.8 to 32.5 on the Noometry Index. gpt-oss-20b costs 42× less per token, which makes it the better buy when Gemini 3.8 Flash's lead doesn't matter for your workload.

Last verified . 27 shared benchmarks.

Gemini 3.8 Flash Google

61.8

Rank #11 Confirmed

gpt-oss-20b OpenAI

32.5

Rank #255 Confirmed

Summary

  • They share 27 benchmarks with published results for both. Gemini 3.8 Flash 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 Gemini 3.8 Flash leads 76.9 to 19.3.
  • The biggest single-benchmark swing is Chess Puzzles: 61% for Gemini 3.8 Flash and 4% for gpt-oss-20b.
  • gpt-oss-20b is cheaper at $0.018 / $0.09 per million input/output tokens, against $0.75 / $3.75 for Gemini 3.8 Flash.
  • Gemini 3.8 Flash accepts more context: 1.05M tokens versus 131K.
  • gpt-oss-20b has downloadable open weights; the other is API-only.

Side by side

Gemini 3.8 Flash and gpt-oss-20b specifications
Gemini 3.8 Flashgpt-oss-20b
ProviderGoogleOpenAI
Noometry Index61.832.5
Released2026-09-022025-08-05
WeightsProprietaryOpen
Context window1.05M131K
Max output66K16K
Input $ / M tokens$0.75$0.018
Output $ / M tokens$3.75$0.09
Results tracked5034

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Category by category

Coding Gemini 3.8 Flash leads

Gemini 3.8 Flash: 59.2 (#15), gpt-oss-20b: 37.6 (#192)

Coding benchmarks
BenchmarkGemini 3.8 Flashgpt-oss-20b
SciCode56.6%34.4%
WeirdML84.8%40.9%
LMArena Coding15101306
ALE-Bench1,270566.05
DeepSWE73.8%—
FrontierCode41.2%—
CursorBench39.6%—
LMArena WebDev1584—
FrontierSWE19.6%—

Agentic & Tool Use Gemini 3.8 Flash leads

Gemini 3.8 Flash: 41.8 (#21), gpt-oss-20b: 9.3 (#154)

Agentic & Tool Use benchmarks
BenchmarkGemini 3.8 Flashgpt-oss-20b
Terminal-Bench—3.4%
APEX-Agents64.3%—
Remote Labor Index5.8%—
GDP.pdf23.4%—
Vending-Bench 25,094—

Reasoning Gemini 3.8 Flash leads

Gemini 3.8 Flash: 76.9 (#5), gpt-oss-20b: 19.3 (#261)

Reasoning benchmarks
BenchmarkGemini 3.8 Flashgpt-oss-20b
CritPt18.3%1.4%
Chess Puzzles61%4%
LMArena Hard Prompts15081274
DTBench95.7%68%
LMCA52.9%14.5%
Epoch Capabilities Index156.71137.82
ARC-AGI-289.2%—
Kagi LLM Benchmark—53.2%
NYT Connections (extended)97.4%—
ARC-AGI-198.5%—
Mystery Game Puzzles47%—
Surface Evolver Bench76.9%—

Math Gemini 3.8 Flash leads

Gemini 3.8 Flash: 65.3 (#28), gpt-oss-20b: 39.4 (#103)

Math benchmarks
BenchmarkGemini 3.8 Flashgpt-oss-20b
OTIS Mock AIME 2024-202598.9%65.3%
LMArena Math15281317
FrontierMath (Tiers 1-3)68.4%—
FrontierMath Tier 422%—
ProofBench48%—
Omni-MATH—56.5%

Knowledge Gemini 3.8 Flash leads

Gemini 3.8 Flash: 74.8 (#2), gpt-oss-20b: 34.6 (#195)

Knowledge benchmarks
BenchmarkGemini 3.8 Flashgpt-oss-20b
GPQA Diamond95.4%60.8%
LMArena Expert15241258
Humanity's Last Exam44.5%—
SimpleQA Verified69.7%—
MMLU-Pro—74%
GPQA (HELM)—59.4%

Multimodal Not comparable

Gemini 3.8 Flash: 40.7 (#45), gpt-oss-20b: —

Multimodal benchmarks
BenchmarkGemini 3.8 Flashgpt-oss-20b
LMArena Vision1314—
Blueprint-Bench 238.6%—
Furniture Assembly31.7%—

Multilingual Gemini 3.8 Flash leads

Gemini 3.8 Flash: 58.0 (#5), gpt-oss-20b: 42.2 (#197)

Multilingual benchmarks
BenchmarkGemini 3.8 Flashgpt-oss-20b
LMArena Non-English14911268
LMArena Chinese15541314
LMArena German14931255
LMArena Japanese15021244
LMArena Korean14591236
LMArena Russian15151278
LMArena Spanish14851267
LMArena French1498—

Instruction Following Gemini 3.8 Flash leads

Gemini 3.8 Flash: 78.0 (#13), gpt-oss-20b: 61.8 (#240)

Instruction Following benchmarks
BenchmarkGemini 3.8 Flashgpt-oss-20b
LMArena Instruction Following14901236
IFEval—73.2%

Long Context Gemini 3.8 Flash leads

Gemini 3.8 Flash: 46.3 (#24), gpt-oss-20b: 37.9 (#209)

Long Context benchmarks
BenchmarkGemini 3.8 Flashgpt-oss-20b
LMArena Longer Query15081250

Writing & Preference Gemini 3.8 Flash leads

Gemini 3.8 Flash: 72.2 (#15), gpt-oss-20b: 35.5 (#265)

Writing & Preference benchmarks
BenchmarkGemini 3.8 Flashgpt-oss-20b
LMArena Text14991287
LMArena Creative Writing14921201
EQ-Bench Creative Writing1748666
LMArena Multi-Turn15011268
WildBench—73.7%

Frequently asked questions

Is Gemini 3.8 Flash better than gpt-oss-20b?

Gemini 3.8 Flash is the stronger model overall, scoring 61.8 to 32.5 on the Noometry Index. gpt-oss-20b costs 42× less per token, which makes it the better buy when Gemini 3.8 Flash's lead doesn't matter for your workload.

Which is cheaper, Gemini 3.8 Flash 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; Gemini 3.8 Flash lists at $0.75 and $3.75.

Is Gemini 3.8 Flash or gpt-oss-20b better for coding?

Gemini 3.8 Flash scores higher on coding benchmarks: 59.2 versus 37.6 in the Noometry coding category.

Which has the bigger context window?

Gemini 3.8 Flash does, with 1.05M tokens against 131K.

How many benchmarks do Gemini 3.8 Flash and gpt-oss-20b share?

27 benchmarks have published results for both models. Gemini 3.8 Flash has 50 scored results on Noometry and gpt-oss-20b has 34.

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