Noometry

Model comparison

Gemma 3 12B vs GPT-5.1-Codex

GPT-5.1-Codex is the stronger model overall, scoring 38.2 to 31.8 on the Noometry Index. Gemma 3 12B costs 46× less per token, which makes it the better buy when GPT-5.1-Codex's lead doesn't matter for your workload.

Last verified . 0 shared benchmarks.

Gemma 3 12B Google

31.8

Rank #255 Confirmed

GPT-5.1-Codex OpenAI

38.2

Rank #178 Reported

Summary

  • The widest gap is in agentic & tool use, where GPT-5.1-Codex leads 37.8 to 25.3.
  • Gemma 3 12B is cheaper at $0.05 / $0.15 per million input/output tokens, against $1.25 / $10 for GPT-5.1-Codex.
  • GPT-5.1-Codex accepts more context: 400K tokens versus 131K.
  • Gemma 3 12B has downloadable open weights; the other is API-only.

Side by side

Gemma 3 12BGPT-5.1-Codex
ProviderGoogleOpenAI
Noometry Index31.838.2
Released2025-03-122025-11-12
WeightsOpenProprietary
Context window131K400K
Max output8K128K
Input $ / M tokens$0.05$1.25
Output $ / M tokens$0.15$10
Results tracked246

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Category by category

Coding GPT-5.1-Codex leads

Gemma 3 12B: 31.2 (#276), GPT-5.1-Codex: 41.7 (#107)

BenchmarkGemma 3 12BGPT-5.1-Codex
SWE-bench Verified (bash only)—66%
LMArena WebDev—1337
SciCode17.4%—
LMArena Coding1281—
ALE-Bench—1,245

Agentic & Tool Use GPT-5.1-Codex leads

Gemma 3 12B: 25.3 (#101), GPT-5.1-Codex: 37.8 (#32)

BenchmarkGemma 3 12BGPT-5.1-Codex
Terminal-Bench—60.4%
Berkeley Function Calling Leaderboard30.4%—
METR Time Horizons—70.8%

Reasoning Not comparable

Gemma 3 12B: 15.2 (#307), GPT-5.1-Codex: —

BenchmarkGemma 3 12BGPT-5.1-Codex
CritPt0%—
Chess Puzzles0%—
LMArena Hard Prompts1309—
DTBench48.8%—
LMCA4.5%—
Epoch Capabilities Index123.49—

Math GPT-5.1-Codex leads

Gemma 3 12B: 21.0 (#273), GPT-5.1-Codex: 29.3 (#218)

BenchmarkGemma 3 12BGPT-5.1-Codex
OTIS Mock AIME 2024-202516.7%—
ProofBench—9%
LMArena Math1307—

Knowledge Not comparable

Gemma 3 12B: 26.5 (#250), GPT-5.1-Codex: —

BenchmarkGemma 3 12BGPT-5.1-Codex
GPQA Diamond39.5%—
Vectara Hallucination Rate4.4%—
LMArena Expert1248—

Multimodal Not comparable

Gemma 3 12B: —, GPT-5.1-Codex: —

BenchmarkGemma 3 12BGPT-5.1-Codex
MindCube46.7%—

Multilingual Not comparable

Gemma 3 12B: 45.9 (#160), GPT-5.1-Codex: —

BenchmarkGemma 3 12BGPT-5.1-Codex
LMArena Non-English1318—
LMArena German1370—
LMArena Russian1335—

Instruction Following Not comparable

Gemma 3 12B: 68.8 (#179), GPT-5.1-Codex: —

BenchmarkGemma 3 12BGPT-5.1-Codex
LMArena Instruction Following1299—

Long Context Not comparable

Gemma 3 12B: 40.0 (#157), GPT-5.1-Codex: —

BenchmarkGemma 3 12BGPT-5.1-Codex
LMArena Longer Query1317—

Writing & Preference Not comparable

Gemma 3 12B: 47.7 (#205), GPT-5.1-Codex: —

BenchmarkGemma 3 12BGPT-5.1-Codex
LMArena Text1334—
LMArena Creative Writing1331—
EQ-Bench Creative Writing1126—
LMArena Multi-Turn1334—

Frequently asked questions

Is Gemma 3 12B better than GPT-5.1-Codex?

GPT-5.1-Codex is the stronger model overall, scoring 38.2 to 31.8 on the Noometry Index. Gemma 3 12B costs 46× less per token, which makes it the better buy when GPT-5.1-Codex's lead doesn't matter for your workload.

Which is cheaper, Gemma 3 12B or GPT-5.1-Codex?

Gemma 3 12B is cheaper. It lists at $0.05 per million input tokens and $0.15 per million output tokens; GPT-5.1-Codex lists at $1.25 and $10.

Is Gemma 3 12B or GPT-5.1-Codex better for coding?

GPT-5.1-Codex scores higher on coding benchmarks: 41.7 versus 31.2 in the Noometry coding category.

Which has the bigger context window?

GPT-5.1-Codex does, with 400K tokens against 131K.

How many benchmarks do Gemma 3 12B and GPT-5.1-Codex share?

0 benchmarks have published results for both models. Gemma 3 12B has 24 scored results on Noometry and GPT-5.1-Codex has 6.

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