Qwen3.5 Plus vs GPT-5-Codex
Qwen3.5 Plus comes out ahead, 59 to 42 on our weighted score, and it is the cheaper option too.
- Our pick
Alibaba (Qwen)Qwen3.5 Plus
59/100- ECI146.8
- Price$0.40 / $2.40
- Context1M
OpenAIGPT-5-Codex
42/100- ECI—
- Price$1.25 / $10.00
- Context400K
Add a model
Make it a three-way comparison.
Qwen3.5 Plus is our pick
Qwen3.5 Plus is the better all-round choice, scoring 59/100 against GPT-5-Codex (42). It leads on price and context window. 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 PlusQwen3.5 Plus $0.90 · GPT-5-Codex $3.44 per 1M tokens (3:1 blend)
- Longest contextQwen3.5 PlusQwen3.5 Plus 1,000,000 · GPT-5-Codex 400,000 tokens
- Widest inputsQwen3.5 PlusQwen3.5 Plus: Text, Images, Video · GPT-5-Codex: Text, Images
- Self-hostingNo open weightsBoth are available only through APIs
| Measure | Weight | Qwen3.5 Plus | GPT-5-Codex |
|---|---|---|---|
| Price | 50% | 52 | 24 |
| Inputs & features | 30% | 70 | 70 |
| Context window | 20% | 60 | 44 |
| Overall | 100% | 59/100 | 42/100 |
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 | Qwen3.5 PlusAlibaba (Qwen) | GPT-5-CodexOpenAI |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | 146.8 | — |
| ECI rank | #65 of 148 | — |
| GPQA DiamondGraduate-level science questions | 84.9% | — |
| OTIS Mock AIME 2024–2025Competition mathematics | 86.7% | — |
| SimpleQA VerifiedShort factual questions | 25.4% | — |
| Price per million tokens | ||
| Input | $0.40 (best) | $1.25 |
| Output | $2.40 (best) | $10.00 |
| Cached input | — | — |
| Blended (3:1) | $0.90 (best) | $3.44 |
| Long-context rate | Same rate | Same rate |
| Price source | Official Alibaba API | Median of 3 providers |
| Limits | ||
| Context window | 1,000,000 tokens (best) | 400,000 tokens |
| Max output | 65,536 tokens | 128,000 tokens (best) |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | Yes |
| PDFs | No | No |
| Audio | No | No |
| Video | Yes | No |
| Reasoning | Yes | Yes |
| Tool calling | Yes | Yes |
| Structured output | No | Yes |
| Availability | ||
| Weights | Proprietary | Proprietary |
| API model ID | qwen3.5-plus | — |
| API providers | 10 (best) | 3 |
| Released | Feb 16, 2026 | Sep 15, 2025 |
| Knowledge cutoff | Apr 2025 | 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.
- Qwen3.5 Plus$8.80
- GPT-5-Codex$32.50
Which should you choose?
Which is better: Qwen3.5 Plus or GPT-5-Codex?
Qwen3.5 Plus is the better all-round choice, scoring 59/100 against GPT-5-Codex (42). It leads on price and context window. 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, Qwen3.5 Plus or GPT-5-Codex?
Qwen3.5 Plus is cheaper at $0.40 input / $2.40 output per million tokens (official Alibaba API price). GPT-5-Codex costs $1.25 input / $10.00 output per million tokens (median across 3 API providers). At a typical mix of three input tokens to one output token, that is $0.90 per million tokens for Qwen3.5 Plus versus $3.44 for GPT-5-Codex (3.8× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers both models yet. Qwen3.5 Plus has an ECI of 146.8 and GPT-5-Codex has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Qwen3.5 Plus and GPT-5-Codex yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Both support tool calling for agent workflows.
Which has the bigger context window?
Qwen3.5 Plus has the largest context window at 1,000,000 tokens, against 400,000 for GPT-5-Codex. Maximum output per response: Qwen3.5 Plus up to 65,536, GPT-5-Codex up to 128,000 tokens.
Which can read images, PDFs, audio or video?
Qwen3.5 Plus accepts text, images and video; GPT-5-Codex accepts text and images. Qwen3.5 Plus handles the widest range of inputs.
Are any of these open source?
No. Qwen3.5 Plus and GPT-5-Codex are proprietary and only available through APIs and apps.
Which is newer?
Qwen3.5 Plus is the newest, released Feb 16, 2026. GPT-5-Codex came out Sep 15, 2025. Knowledge cutoff: Qwen3.5 Plus Apr 2025, GPT-5-Codex 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 Oct 4, 2026.
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