Noometry

Model comparison

GPT-5.1-Codex vs Qwen3.5 35B-A3B

Qwen3.5 35B-A3B is the stronger model overall, scoring 42.0 to 38.6 on the Noometry Index.

Last verified . 1 shared benchmarks.

GPT-5.1-Codex OpenAI

38.6

Rank #186 Reported

Qwen3.5 35B-A3B Alibaba (Qwen)

42.0

Rank #123 Confirmed

Summary

  • They share 1 benchmark with published results for both. GPT-5.1-Codex scores higher in 1 category and Qwen3.5 35B-A3B in 1 category; 2 gaps are clear of the uncertainty.
  • The widest gap is in math, where Qwen3.5 35B-A3B leads 39.9 to 30.3.
  • Qwen3.5 35B-A3B is cheaper at $0.25 / $2 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.
  • Qwen3.5 35B-A3B has downloadable open weights; the other is API-only.

Side by side

GPT-5.1-CodexQwen3.5 35B-A3B
ProviderOpenAIAlibaba (Qwen)
Noometry Index38.642.0
Released2025-11-122026-02-01
WeightsProprietaryOpen
Context window400K262K
Max output128K66K
Input $ / M tokens$1.25$0.25
Output $ / M tokens$10$2
Results tracked628

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Category by category

Coding GPT-5.1-Codex leads

GPT-5.1-Codex: 41.9 (#116), Qwen3.5 35B-A3B: 33.8 (#251)

BenchmarkGPT-5.1-CodexQwen3.5 35B-A3B
LMArena WebDev13371254
SWE-bench Verified (bash only)66%—
SciCode—29.3%
LMArena Coding—1410
ALE-Bench1,245—

Agentic & Tool Use Not comparable

GPT-5.1-Codex: 38.0 (#33), Qwen3.5 35B-A3B: —

BenchmarkGPT-5.1-CodexQwen3.5 35B-A3B
Terminal-Bench60.4%—
METR Time Horizons70.8%—

Reasoning Not comparable

GPT-5.1-Codex: —, Qwen3.5 35B-A3B: 24.6 (#161)

BenchmarkGPT-5.1-CodexQwen3.5 35B-A3B
CritPt—0.6%
Chess Puzzles—10%
LMArena Hard Prompts—1400
DTBench—80%
LMCA—29.5%
Epoch Capabilities Index—142.52

Math Qwen3.5 35B-A3B leads

GPT-5.1-Codex: 30.3 (#235), Qwen3.5 35B-A3B: 39.9 (#97)

BenchmarkGPT-5.1-CodexQwen3.5 35B-A3B
MathArena Final-Answer Competitions—56%
OTIS Mock AIME 2024-2025—70%
ProofBench9%—
LMArena Math—1404

Knowledge Not comparable

GPT-5.1-Codex: —, Qwen3.5 35B-A3B: 47.8 (#79)

BenchmarkGPT-5.1-CodexQwen3.5 35B-A3B
GPQA Diamond—83.5%
Vectara Hallucination Rate—10.5%
LMArena Expert—1408

Multilingual Not comparable

GPT-5.1-Codex: —, Qwen3.5 35B-A3B: 50.0 (#127)

BenchmarkGPT-5.1-CodexQwen3.5 35B-A3B
LMArena Non-English—1378
LMArena Chinese—1457
LMArena French—1412
LMArena German—1367
LMArena Japanese—1325
LMArena Korean—1356
LMArena Russian—1376
LMArena Spanish—1392

Instruction Following Not comparable

GPT-5.1-Codex: —, Qwen3.5 35B-A3B: 72.8 (#128)

BenchmarkGPT-5.1-CodexQwen3.5 35B-A3B
LMArena Instruction Following—1379

Long Context Not comparable

GPT-5.1-Codex: —, Qwen3.5 35B-A3B: 42.4 (#127)

BenchmarkGPT-5.1-CodexQwen3.5 35B-A3B
LMArena Longer Query—1389

Writing & Preference Not comparable

GPT-5.1-Codex: —, Qwen3.5 35B-A3B: 57.9 (#124)

BenchmarkGPT-5.1-CodexQwen3.5 35B-A3B
LMArena Text—1395
LMArena Creative Writing—1346
LMArena Multi-Turn—1390

Frequently asked questions

Is GPT-5.1-Codex better than Qwen3.5 35B-A3B?

Qwen3.5 35B-A3B is the stronger model overall, scoring 42.0 to 38.6 on the Noometry Index.

Which is cheaper, GPT-5.1-Codex or Qwen3.5 35B-A3B?

Qwen3.5 35B-A3B is cheaper. It lists at $0.25 per million input tokens and $2 per million output tokens; GPT-5.1-Codex lists at $1.25 and $10.

Is GPT-5.1-Codex or Qwen3.5 35B-A3B better for coding?

GPT-5.1-Codex scores higher on coding benchmarks: 41.9 versus 33.8 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 Qwen3.5 35B-A3B share?

1 benchmark has published results for both models. GPT-5.1-Codex has 6 scored results on Noometry and Qwen3.5 35B-A3B has 28.

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