Model comparison

GPT-5.1-Codex vs Nemotron 3 Nano 30B A3B

Nemotron 3 Nano 30B A3B is the stronger model overall, scoring 40.6 to 38.6 on the Noometry Index.

Last verified October 10, 2026. 0 shared benchmarks.

GPT-5.1-Codex OpenAI

38.6

Rank #186 Reported

Nemotron 3 Nano 30B A3B

NVIDIA

40.6

Rank #147 Confirmed

Summary

The widest gap is in math, where Nemotron 3 Nano 30B A3B leads 37.8 to 30.3.
Nemotron 3 Nano 30B A3B is cheaper at $0.05 / $0.20 per million input/output tokens, against $1.25 / $10 for GPT-5.1-Codex.
GPT-5.1-Codex accepts more context: 400K tokens versus 262K.
Nemotron 3 Nano 30B A3B has downloadable open weights; the other is API-only.

Side by side

GPT-5.1-Codex and Nemotron 3 Nano 30B A3B specifications
	GPT-5.1-Codex	Nemotron 3 Nano 30B A3B
Provider	OpenAI	NVIDIA
Noometry Index	38.6	40.6
Released	2025-11-12	2025-12-15
Weights	Proprietary	Open
Context window	400K	262K
Max output	128K	262K
Input $ / M tokens	$1.25	$0.05
Output $ / M tokens	$10	$0.20
Results tracked	6	18

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Category by category

Coding GPT-5.1-Codex leads

GPT-5.1-Codex: 41.9 (#116), Nemotron 3 Nano 30B A3B: 40.5 (#138)

Coding benchmarks
Benchmark	GPT-5.1-Codex	Nemotron 3 Nano 30B A3B
SWE-bench Verified (bash only)	66%	—
LMArena WebDev	1337	—
LMArena Coding	—	1378
ALE-Bench	1,245	—

Agentic & Tool Use Not comparable

GPT-5.1-Codex: 38.0 (#33), Nemotron 3 Nano 30B A3B: —

Agentic & Tool Use benchmarks
Benchmark	GPT-5.1-Codex	Nemotron 3 Nano 30B A3B
Terminal-Bench	60.4%	—
METR Time Horizons	70.8%	—

Reasoning Not comparable

GPT-5.1-Codex: —, Nemotron 3 Nano 30B A3B: 27.1 (#124)

Reasoning benchmarks
Benchmark	GPT-5.1-Codex	Nemotron 3 Nano 30B A3B
LMArena Hard Prompts	—	1348

Math Nemotron 3 Nano 30B A3B leads

GPT-5.1-Codex: 30.3 (#235), Nemotron 3 Nano 30B A3B: 37.8 (#147)

Math benchmarks
Benchmark	GPT-5.1-Codex	Nemotron 3 Nano 30B A3B
ProofBench	9%	—
LMArena Math	—	1371

Knowledge Not comparable

GPT-5.1-Codex: —, Nemotron 3 Nano 30B A3B: 38.2 (#148)

Knowledge benchmarks
Benchmark	GPT-5.1-Codex	Nemotron 3 Nano 30B A3B
Vectara Hallucination Rate	—	9.6%
LMArena Expert	—	1355

Multilingual Not comparable

GPT-5.1-Codex: —, Nemotron 3 Nano 30B A3B: 45.8 (#162)

Multilingual benchmarks
Benchmark	GPT-5.1-Codex	Nemotron 3 Nano 30B A3B
LMArena Non-English	—	1320
LMArena Chinese	—	1382
LMArena French	—	1396
LMArena German	—	1348
LMArena Japanese	—	1268
LMArena Korean	—	1269
LMArena Russian	—	1303
LMArena Spanish	—	1376

Instruction Following Not comparable

GPT-5.1-Codex: —, Nemotron 3 Nano 30B A3B: 68.8 (#180)

Instruction Following benchmarks
Benchmark	GPT-5.1-Codex	Nemotron 3 Nano 30B A3B
LMArena Instruction Following	—	1304

Long Context Not comparable

GPT-5.1-Codex: —, Nemotron 3 Nano 30B A3B: 39.5 (#175)

Long Context benchmarks
Benchmark	GPT-5.1-Codex	Nemotron 3 Nano 30B A3B
LMArena Longer Query	—	1300

Writing & Preference Not comparable

GPT-5.1-Codex: —, Nemotron 3 Nano 30B A3B: 52.3 (#174)

Writing & Preference benchmarks
Benchmark	GPT-5.1-Codex	Nemotron 3 Nano 30B A3B
LMArena Text	—	1348
LMArena Creative Writing	—	1269
LMArena Multi-Turn	—	1319

Frequently asked questions

Is GPT-5.1-Codex better than Nemotron 3 Nano 30B A3B?

Nemotron 3 Nano 30B A3B is the stronger model overall, scoring 40.6 to 38.6 on the Noometry Index.

Which is cheaper, GPT-5.1-Codex or Nemotron 3 Nano 30B A3B?

Nemotron 3 Nano 30B A3B is cheaper. It lists at $0.05 per million input tokens and $0.20 per million output tokens; GPT-5.1-Codex lists at $1.25 and $10.

Is GPT-5.1-Codex or Nemotron 3 Nano 30B A3B better for coding?

GPT-5.1-Codex scores higher on coding benchmarks: 41.9 versus 40.5 in the Noometry coding category.

Which has the bigger context window?

GPT-5.1-Codex does, with 400K tokens against 262K.

How many benchmarks do GPT-5.1-Codex and Nemotron 3 Nano 30B A3B share?

0 benchmarks have published results for both models. GPT-5.1-Codex has 6 scored results on Noometry and Nemotron 3 Nano 30B A3B has 18.