Model comparison
GPT-5.1-Codex vs Qwen3.5-9B
GPT-5.1-Codex is the stronger model overall, scoring 38.2 to 33.3 on the Noometry Index. Qwen3.5-9B costs 31× less per token, which makes it the better buy when GPT-5.1-Codex's lead doesn't matter for your workload.
Last verified . 1 shared benchmarks.
Alibaba (Qwen)Summary
- They share 1 benchmark with published results for both. GPT-5.1-Codex scores higher in 2 categories and Qwen3.5-9B in 1 category; 3 gaps are clear of the uncertainty.
- The widest gap is in agentic & tool use, where GPT-5.1-Codex leads 37.8 to 14.4.
- The biggest single-benchmark swing is Terminal-Bench: 60.4% for GPT-5.1-Codex and 9.2% for Qwen3.5-9B.
- Qwen3.5-9B is cheaper at $0.10 / $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 262K.
- Qwen3.5-9B has downloadable open weights; the other is API-only.
Side by side
| GPT-5.1-Codex | Qwen3.5-9B | |
|---|---|---|
| Provider | OpenAI | Alibaba (Qwen) |
| Noometry Index | 38.2 | 33.3 |
| Released | 2025-11-12 | 2026-02-23 |
| Weights | Proprietary | Open |
| Context window | 400K | 262K |
| Max output | 128K | 66K |
| Input $ / M tokens | $1.25 | $0.10 |
| Output $ / M tokens | $10 | $0.15 |
| Results tracked | 6 | 10 |
Sponsored placements are available on pages like this one. Advertise on Noometry
Category by category
Coding GPT-5.1-Codex leads
GPT-5.1-Codex: 41.7 (#107), Qwen3.5-9B: 35.3 (#213)
| Benchmark | GPT-5.1-Codex | Qwen3.5-9B |
|---|---|---|
| SWE-bench Verified (bash only) | 66% | — |
| LMArena WebDev | 1337 | — |
| SciCode | — | 27.5% |
| ALE-Bench | 1,245 | — |
Agentic & Tool Use GPT-5.1-Codex leads
GPT-5.1-Codex: 37.8 (#32), Qwen3.5-9B: 14.4 (#143)
| Benchmark | GPT-5.1-Codex | Qwen3.5-9B |
|---|---|---|
| Terminal-Bench | 60.4% | 9.2% |
| METR Time Horizons | 70.8% | — |
Reasoning Not comparable
GPT-5.1-Codex: —, Qwen3.5-9B: 22.5 (#178)
| Benchmark | GPT-5.1-Codex | Qwen3.5-9B |
|---|---|---|
| CritPt | — | 0.3% |
| Chess Puzzles | — | 12% |
| DTBench | — | 71.2% |
| LMCA | — | 24.5% |
| Epoch Capabilities Index | — | 139.45 |
Math Qwen3.5-9B leads
GPT-5.1-Codex: 29.3 (#218), Qwen3.5-9B: 33.5 (#174)
| Benchmark | GPT-5.1-Codex | Qwen3.5-9B |
|---|---|---|
| MathArena Final-Answer Competitions | — | 48.5% |
| OTIS Mock AIME 2024-2025 | — | 61.7% |
| ProofBench | 9% | — |
Knowledge Not comparable
GPT-5.1-Codex: —, Qwen3.5-9B: 46.0 (#77)
| Benchmark | GPT-5.1-Codex | Qwen3.5-9B |
|---|---|---|
| GPQA Diamond | — | 79% |
Frequently asked questions
Is GPT-5.1-Codex better than Qwen3.5-9B?
GPT-5.1-Codex is the stronger model overall, scoring 38.2 to 33.3 on the Noometry Index. Qwen3.5-9B costs 31× 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, GPT-5.1-Codex or Qwen3.5-9B?
Qwen3.5-9B is cheaper. It lists at $0.10 per million input tokens and $0.15 per million output tokens; GPT-5.1-Codex lists at $1.25 and $10.
Is GPT-5.1-Codex or Qwen3.5-9B better for coding?
GPT-5.1-Codex scores higher on coding benchmarks: 41.7 versus 35.3 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 Qwen3.5-9B share?
1 benchmark has published results for both models. GPT-5.1-Codex has 6 scored results on Noometry and Qwen3.5-9B has 10.