Noometry

Model comparison

Gemma 3 12B vs GPT-5.3 Codex

GPT-5.3 Codex is the stronger model overall, scoring 45.8 to 32.1 on the Noometry Index. Gemma 3 12B costs 64× less per token, which makes it the better buy when GPT-5.3 Codex's lead doesn't matter for your workload.

Last verified . 1 shared benchmarks.

Gemma 3 12B Google

32.1

Rank #262 Confirmed

GPT-5.3 Codex OpenAI

45.8

Rank #69 Reported

Summary

  • They share 1 benchmark with published results for both. Gemma 3 12B scores higher in 0 categories and GPT-5.3 Codex in 2 categories; 2 gaps are clear of the uncertainty.
  • The widest gap is in agentic & tool use, where GPT-5.3 Codex leads 48.0 to 25.5.
  • Gemma 3 12B is cheaper at $0.05 / $0.15 per million input/output tokens, against $1.75 / $14 for GPT-5.3 Codex.
  • GPT-5.3 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-5.3 Codex
ProviderGoogleOpenAI
Noometry Index32.145.8
Released2025-03-122026-02-05
WeightsOpenProprietary
Context window131K400K
Max output8K128K
Input $ / M tokens$0.05$1.75
Output $ / M tokens$0.15$14
Results tracked248

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Category by category

Coding GPT-5.3 Codex leads

Gemma 3 12B: 31.7 (#280), GPT-5.3 Codex: 48.6 (#56)

BenchmarkGemma 3 12BGPT-5.3 Codex
SWE-bench Verified—74.8%
LMArena WebDev—1409
SciCode17.4%—
WeirdML—79.3%
LMArena Coding1281—
ALE-Bench—1,655

Agentic & Tool Use GPT-5.3 Codex leads

Gemma 3 12B: 25.5 (#108), GPT-5.3 Codex: 48.0 (#9)

BenchmarkGemma 3 12BGPT-5.3 Codex
Terminal-Bench—78.4%
Berkeley Function Calling Leaderboard30.4%—
METR Time Horizons—74.5%
Vending-Bench 2—5,940

Reasoning Not comparable

Gemma 3 12B: 15.7 (#313), GPT-5.3 Codex: —

BenchmarkGemma 3 12BGPT-5.3 Codex
Epoch Capabilities Index123.5156.77
CritPt0%—
Chess Puzzles0%—
LMArena Hard Prompts1309—
DTBench48.8%—
LMCA4.5%—

Math Not comparable

Gemma 3 12B: 22.3 (#279), GPT-5.3 Codex: —

BenchmarkGemma 3 12BGPT-5.3 Codex
OTIS Mock AIME 2024-202516.7%—
LMArena Math1307—

Knowledge Not comparable

Gemma 3 12B: 26.5 (#257), GPT-5.3 Codex: —

BenchmarkGemma 3 12BGPT-5.3 Codex
GPQA Diamond39.5%—
Vectara Hallucination Rate4.4%—
LMArena Expert1248—

Multimodal Not comparable

Gemma 3 12B: —, GPT-5.3 Codex: —

BenchmarkGemma 3 12BGPT-5.3 Codex
MindCube46.7%—

Multilingual Not comparable

Gemma 3 12B: 45.7 (#165), GPT-5.3 Codex: —

BenchmarkGemma 3 12BGPT-5.3 Codex
LMArena Non-English1318—
LMArena German1370—
LMArena Russian1335—

Instruction Following Not comparable

Gemma 3 12B: 68.6 (#186), GPT-5.3 Codex: —

BenchmarkGemma 3 12BGPT-5.3 Codex
LMArena Instruction Following1299—

Long Context Not comparable

Gemma 3 12B: 40.0 (#162), GPT-5.3 Codex: —

BenchmarkGemma 3 12BGPT-5.3 Codex
LMArena Longer Query1317—

Writing & Preference Not comparable

Gemma 3 12B: 47.5 (#209), GPT-5.3 Codex: —

BenchmarkGemma 3 12BGPT-5.3 Codex
LMArena Text1334—
LMArena Creative Writing1331—
EQ-Bench Creative Writing1126—
LMArena Multi-Turn1334—

Frequently asked questions

Is Gemma 3 12B better than GPT-5.3 Codex?

GPT-5.3 Codex is the stronger model overall, scoring 45.8 to 32.1 on the Noometry Index. Gemma 3 12B costs 64× less per token, which makes it the better buy when GPT-5.3 Codex's lead doesn't matter for your workload.

Which is cheaper, Gemma 3 12B or GPT-5.3 Codex?

Gemma 3 12B is cheaper. It lists at $0.05 per million input tokens and $0.15 per million output tokens; GPT-5.3 Codex lists at $1.75 and $14.

Is Gemma 3 12B or GPT-5.3 Codex better for coding?

GPT-5.3 Codex scores higher on coding benchmarks: 48.6 versus 31.7 in the Noometry coding category.

Which has the bigger context window?

GPT-5.3 Codex does, with 400K tokens against 131K.

How many benchmarks do Gemma 3 12B and GPT-5.3 Codex share?

1 benchmark has published results for both models. Gemma 3 12B has 24 scored results on Noometry and GPT-5.3 Codex has 8.

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