# GPT-5-Codex vs Qwen3.5 397B-A17B

> Qwen3.5 397B-A17B is the stronger model overall, scoring 45.7 to 37.3 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-5-codex-vs-qwen3-5-397b-a17b
- Last updated: 2026-10-10
- Shared benchmarks: 1

## Summary

- They share 1 benchmark with published results for both. GPT-5-Codex scores higher in 1 category and Qwen3.5 397B-A17B in 2 categories; 2 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Qwen3.5 397B-A17B leads 33.6 to 30.0.
- Qwen3.5 397B-A17B is cheaper at $0.60 / $3.60 per million input/output tokens, against $1.25 / $10 for GPT-5-Codex.
- GPT-5-Codex accepts more context: 400K tokens versus 262K.
- Qwen3.5 397B-A17B has downloadable open weights; the other is API-only.

## Snapshot

| | GPT-5-Codex | Qwen3.5 397B-A17B |
|---|---|---|
| Provider | OpenAI | Alibaba (Qwen) |
| Noometry Index | 37.3 | 45.7 |
| Rank | 190 | 60 |
| Context | 400K | 262K |
| Input $/M | $1.25 | $0.60 |
| Output $/M | $10 | $3.60 |
| Weights | Proprietary | Open |

## Coding

- GPT-5-Codex: 41.9 (#100)
- Qwen3.5 397B-A17B: 41.7 (#108)

| Benchmark | GPT-5-Codex | Qwen3.5 397B-A17B |
|---|---|---|
| LMArena WebDev | — | 1400 |
| WeirdML | 54.5% | — |
| LMArena Coding | — | 1464 |

## Agentic & Tool Use

- GPT-5-Codex: 30.8 (#66)
- Qwen3.5 397B-A17B: 33.2 (#51)

| Benchmark | GPT-5-Codex | Qwen3.5 397B-A17B |
|---|---|---|
| Terminal-Bench | 44.3% | — |
| APEX-Agents | — | 24.9% |
| τ²-bench Airline | — | 81.5% |
| τ²-bench Banking | — | 9.8% |
| τ²-bench Retail | — | 84.4% |
| τ²-bench Telecom | — | 97.8% |

## Reasoning

- GPT-5-Codex: 30.0 (#80)
- Qwen3.5 397B-A17B: 33.6 (#62)

| Benchmark | GPT-5-Codex | Qwen3.5 397B-A17B |
|---|---|---|
| Kagi LLM Benchmark | 70.3% | 73.7% |
| NYT Connections (extended) | — | 58.9% |
| Chess Puzzles | — | 13% |
| Thematic Generalization | — | 65.1% |
| LMArena Hard Prompts | — | 1448 |
| Mystery Game Puzzles | — | 18% |
| DTBench | — | 87.5% |
| LMCA | — | 37.9% |
| Epoch Capabilities Index | — | 146.64 |

## Math

- GPT-5-Codex: —
- Qwen3.5 397B-A17B: 44.9 (#64)

| Benchmark | GPT-5-Codex | Qwen3.5 397B-A17B |
|---|---|---|
| FrontierMath (Tiers 1-3) | — | 31.2% |
| OTIS Mock AIME 2024-2025 | — | 88.9% |
| LMArena Math | — | 1455 |

## Knowledge

- GPT-5-Codex: —
- Qwen3.5 397B-A17B: 53.3 (#53)

| Benchmark | GPT-5-Codex | Qwen3.5 397B-A17B |
|---|---|---|
| GPQA Diamond | — | 86.4% |
| LMArena Expert | — | 1461 |

## Multimodal

- GPT-5-Codex: —
- Qwen3.5 397B-A17B: 40.0 (#42)

| Benchmark | GPT-5-Codex | Qwen3.5 397B-A17B |
|---|---|---|
| LMArena Vision | — | 1262 |

## Multilingual

- GPT-5-Codex: —
- Qwen3.5 397B-A17B: 54.0 (#56)

| Benchmark | GPT-5-Codex | Qwen3.5 397B-A17B |
|---|---|---|
| LMArena Non-English | — | 1431 |
| LMArena Chinese | — | 1501 |
| LMArena French | — | 1461 |
| LMArena German | — | 1447 |
| LMArena Japanese | — | 1427 |
| LMArena Korean | — | 1382 |
| LMArena Russian | — | 1429 |
| LMArena Spanish | — | 1443 |

## Instruction Following

- GPT-5-Codex: —
- Qwen3.5 397B-A17B: 75.2 (#73)

| Benchmark | GPT-5-Codex | Qwen3.5 397B-A17B |
|---|---|---|
| LMArena Instruction Following | — | 1424 |

## Long Context

- GPT-5-Codex: —
- Qwen3.5 397B-A17B: 44.1 (#71)

| Benchmark | GPT-5-Codex | Qwen3.5 397B-A17B |
|---|---|---|
| LMArena Longer Query | — | 1442 |

## Writing & Preference

- GPT-5-Codex: —
- Qwen3.5 397B-A17B: 62.5 (#74)

| Benchmark | GPT-5-Codex | Qwen3.5 397B-A17B |
|---|---|---|
| LMArena Text | — | 1438 |
| LMArena Creative Writing | — | 1401 |
| EQ-Bench Creative Writing | — | 1478 |
| LMArena Multi-Turn | — | 1447 |

## FAQ

### Is GPT-5-Codex better than Qwen3.5 397B-A17B?

Qwen3.5 397B-A17B is the stronger model overall, scoring 45.7 to 37.3 on the Noometry Index.

### Which is cheaper, GPT-5-Codex or Qwen3.5 397B-A17B?

Qwen3.5 397B-A17B is cheaper. It lists at $0.60 per million input tokens and $3.60 per million output tokens; GPT-5-Codex lists at $1.25 and $10.

### Is GPT-5-Codex or Qwen3.5 397B-A17B better for coding?

They score almost the same on coding (41.9 vs 41.7); test both on your own repository before choosing.

### Which has the bigger context window?

GPT-5-Codex does, with 400K tokens against 262K.

### How many benchmarks do GPT-5-Codex and Qwen3.5 397B-A17B share?

1 benchmark has published results for both models. GPT-5-Codex has 3 scored results on Noometry and Qwen3.5 397B-A17B has 36.