GPT-5.1 Codex mini vs Qwen3.5 9B Base
GPT-5.1 Codex mini comes out ahead, 54 to 50 on our weighted score, though Qwen3.5 9B Base is 38% cheaper per token.
- Our pick
OpenAIGPT-5.1 Codex mini
54/100- ECI—
- Price$0.25 / $2.00
- Context400K
Alibaba (Qwen)Qwen3.5 9B Base
50/100- ECI—
- Price$0.30 / $0.807
- Context262K
Add a model
Make it a three-way comparison.
GPT-5.1 Codex mini is our pick
GPT-5.1 Codex mini is the better all-round choice, scoring 54/100 against Qwen3.5 9B Base (50). It leads on inputs & features and context window. Qwen3.5 9B Base wins on price. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
- CapabilityNot enough dataNo independent benchmark covers every model here yet
- Lowest priceQwen3.5 9B BaseQwen3.5 9B Base $0.427 · GPT-5.1 Codex mini $0.688 per 1M tokens (3:1 blend)
- Longest contextGPT-5.1 Codex miniGPT-5.1 Codex mini 400,000 · Qwen3.5 9B Base 262,144 tokens
- Widest inputsQwen3.5 9B BaseGPT-5.1 Codex mini: Text, Images · Qwen3.5 9B Base: Text, Images, Video
- Self-hostingQwen3.5 9B BasePublishes downloadable weights (Apache-2.0)
| Measure | Weight | GPT-5.1 Codex mini | Qwen3.5 9B Base |
|---|---|---|---|
| Price | 50% | 55 | 65 |
| Inputs & features | 30% | 60 | 35 |
| Context window | 20% | 44 | 37 |
| Overall | 100% | 54/100 | 50/100 |
Left out because at least one model lacks the data: capability. The remaining weights were rescaled.
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | GPT-5.1 Codex miniOpenAI | Qwen3.5 9B BaseAlibaba (Qwen) |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | — | — |
| ECI rank | — | — |
| Price per million tokens | ||
| Input | $0.25 (best) | $0.30 |
| Output | $2.00 | $0.807 (best) |
| Cached input | — | — |
| Blended (3:1) | $0.688 | $0.427 (best) |
| Long-context rate | Same rate | Same rate |
| Price source | Median of 16 providers | Median of 1 providers |
| Limits | ||
| Context window | 400,000 tokens (best) | 262,144 tokens |
| Max output | 128,000 tokens (best) | 65,536 tokens |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | Yes |
| PDFs | No | No |
| Audio | No | No |
| Video | No | Yes |
| Reasoning | Yes | No |
| Tool calling | Yes | No |
| Structured output | No | No |
| Availability | ||
| Weights | Proprietary | OpenApache-2.0 |
| API model ID | — | — |
| API providers | 16 (best) | 1 |
| Released | Nov 13, 2025 | Feb 26, 2026 |
| Knowledge cutoff | Sep 30, 2024 | — |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- GPT-5.1 Codex mini$6.50
- Qwen3.5 9B Base$4.61
Which should you choose?
Which is better: GPT-5.1 Codex mini or Qwen3.5 9B Base?
GPT-5.1 Codex mini is the better all-round choice, scoring 54/100 against Qwen3.5 9B Base (50). It leads on inputs & features and context window. Qwen3.5 9B Base wins on price. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
Which is cheaper, GPT-5.1 Codex mini or Qwen3.5 9B Base?
Qwen3.5 9B Base is cheaper at $0.30 input / $0.807 output per million tokens (median across 1 API provider). GPT-5.1 Codex mini costs $0.25 input / $2.00 output per million tokens (median across 16 API providers). At a typical mix of three input tokens to one output token, that is $0.427 per million tokens for Qwen3.5 9B Base versus $0.688 for GPT-5.1 Codex mini (1.6× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers both models yet. GPT-5.1 Codex mini has not been scored yet and Qwen3.5 9B Base has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for GPT-5.1 Codex mini and Qwen3.5 9B Base yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Note that Qwen3.5 9B Base does not support tool calling, which most coding agents need.
Which has the bigger context window?
GPT-5.1 Codex mini has the largest context window at 400,000 tokens, against 262,144 for Qwen3.5 9B Base. Maximum output per response: GPT-5.1 Codex mini up to 128,000, Qwen3.5 9B Base up to 65,536 tokens.
Which can read images, PDFs, audio or video?
GPT-5.1 Codex mini accepts text and images; Qwen3.5 9B Base accepts text, images and video. Qwen3.5 9B Base handles the widest range of inputs.
Are any of these open source?
Qwen3.5 9B Base publishes its weights (Apache-2.0) and can be self-hosted; GPT-5.1 Codex mini is proprietary.
Which is newer?
Qwen3.5 9B Base is the newest, released Feb 26, 2026. GPT-5.1 Codex mini came out Nov 13, 2025. Knowledge cutoff: GPT-5.1 Codex mini Sep 30, 2024.
How do you decide the winner?
Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Nov 2, 2026.
Related comparisons
- Add Mistral Large 3Three-way comparison
- GPT-5.1 Codex mini vs Mistral Large 3Mistral AI
- GPT-5.1 Codex mini vs Qwen3 VL 235B A22B InstructAlibaba (Qwen)
- GPT-5.1 Codex mini vs Nova 2 LiteAmazon
- GPT-5.1 Codex mini vs Relace Apply 3Relace
- Qwen3.5 9B Base vs Mercury 2Inception
- Qwen3.5 9B Base vs Trinity Large ThinkingArcee AI
