GPT-5.1 vs GPT-5.3 Codex vs Qwen3.6 Max Preview
GPT-5.3 Codex comes out ahead, 64 to 60 and 54 on our weighted score, though Qwen3.6 Max Preview is 39% cheaper per token.
OpenAIGPT-5.1
60/100- ECI149.7
- Price$1.25 / $10.00
- Context400K
- Our pickOpenAI
GPT-5.3 Codex
64/100- ECI156.8
- Price$1.75 / $14.00
- Context400K
Alibaba (Qwen)Qwen3.6 Max Preview
54/100- ECI149.2
- Price$1.30 / $7.80
- Context262K
GPT-5.3 Codex is our pick
GPT-5.3 Codex is the better all-round choice, scoring 64/100 against GPT-5.1 (60) and Qwen3.6 Max Preview (54). It leads on capability and inputs & features. Qwen3.6 Max Preview wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityGPT-5.3 CodexCapabilities Index (ECI): GPT-5.3 Codex 156.8 · GPT-5.1 149.7 · Qwen3.6 Max Preview 149.2
- Lowest priceQwen3.6 Max PreviewQwen3.6 Max Preview $2.92 · GPT-5.1 $3.44 · GPT-5.3 Codex $4.81 per 1M tokens (3:1 blend)
- Longest contextGPT-5.1 and GPT-5.3 CodexGPT-5.1 400,000 · GPT-5.3 Codex 400,000 · Qwen3.6 Max Preview 262,144 tokens
- Widest inputsGPT-5.3 CodexGPT-5.1: Text, Images · GPT-5.3 Codex: Text, Images, PDFs · Qwen3.6 Max Preview: Text
- Self-hostingNo open weightsAll three are available only through APIs
| Measure | Weight | GPT-5.1 | GPT-5.3 Codex | Qwen3.6 Max Preview |
|---|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 78 | 87 | 77 |
| Price | 25% | 24 | 18 | 28 |
| Inputs & features | 15% | 70 | 80 | 35 |
| Context window | 10% | 44 | 44 | 37 |
| Overall | 100% | 60/100 | 64/100 | 54/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | GPT-5.1OpenAI | GPT-5.3 CodexOpenAI | Qwen3.6 Max PreviewAlibaba (Qwen) |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | 149.7 | 156.8 (best) | 149.2 |
| ECI rank | #52 of 148 | #18 of 148 (best) | #54 of 148 |
| GPQA DiamondGraduate-level science questions | 87.6% (best) | — | 87.4% |
| OTIS Mock AIME 2024–2025Competition mathematics | 88.6% | — | 91.1% (best) |
| SWE-bench VerifiedFixing real GitHub issues | 68.0% | 74.8% | 76.7% (best) |
| SimpleQA VerifiedShort factual questions | 48.0% | — | 52.0% (best) |
| Price per million tokens | |||
| Input | $1.25 (best) | $1.75 | $1.30 |
| Output | $10.00 | $14.00 | $7.80 (best) |
| Cached input | $0.125 (best) | $0.175 | $0.13 |
| Blended (3:1) | $3.44 | $4.81 | $2.92 (best) |
| Long-context rate | Same rate | Same rate | Same rate |
| Price source | Official OpenAI API | Official OpenAI API | Official Alibaba API |
| Limits | |||
| Context window | 400,000 tokens (best) | 400,000 tokens (best) | 262,144 tokens |
| Max output | 128,000 tokens (best) | 128,000 tokens (best) | 65,536 tokens |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | No |
| PDFs | No | Yes | No |
| Audio | No | No | No |
| Video | No | No | No |
| Reasoning | Yeslow · medium · high | Yeslow · medium · high · xhigh | Yes |
| Tool calling | Yes | Yes | Yes |
| Structured output | Yes | Yes | No |
| Availability | |||
| Weights | Proprietary | Proprietary | Proprietary |
| API model ID | gpt-5.1 | gpt-5.3-codex | qwen3.6-max-preview |
| API providers | 21 (best) | 19 | 10 |
| Released | Nov 13, 2025 | Feb 5, 2026 | Apr 20, 2026 |
| Knowledge cutoff | Sep 30, 2024 | Aug 31, 2025 | Apr 2025 |
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$32.50
- GPT-5.3 Codex$45.50
- Qwen3.6 Max Preview$28.60
Which should you choose?
Which is better: GPT-5.1, GPT-5.3 Codex or Qwen3.6 Max Preview?
GPT-5.3 Codex is the better all-round choice, scoring 64/100 against GPT-5.1 (60) and Qwen3.6 Max Preview (54). It leads on capability and inputs & features. Qwen3.6 Max Preview wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, GPT-5.1, GPT-5.3 Codex or Qwen3.6 Max Preview?
Qwen3.6 Max Preview is cheaper at $1.30 input / $7.80 output per million tokens (official Alibaba API price). GPT-5.1 costs $1.25 input / $10.00 output per million tokens (official OpenAI API price); GPT-5.3 Codex costs $1.75 input / $14.00 output per million tokens (official OpenAI API price). At a typical mix of three input tokens to one output token, that is $2.92 per million tokens for Qwen3.6 Max Preview versus $3.44 for GPT-5.1 (1.2× as much) and $4.81 for GPT-5.3 Codex (1.6× as much).
Which scores higher on benchmarks?
GPT-5.3 Codex scores higher on the Capabilities Index (ECI): GPT-5.3 Codex 156.8 (#18 of 148), GPT-5.1 149.7 (#52 of 148) and Qwen3.6 Max Preview 149.2 (#54 of 148). Their confidence ranges do not overlap (153.5–160.8 vs 148.3–151.1), so the gap is a real one. On individual benchmarks: SWE-bench Verified — Qwen3.6 Max Preview 76.7%, GPT-5.3 Codex 74.8%, GPT-5.1 68.0%.
Which is better for coding?
Qwen3.6 Max Preview resolves more real GitHub issues on SWE-bench Verified: Qwen3.6 Max Preview 76.7%, GPT-5.3 Codex 74.8% and GPT-5.1 68.0%. All three support tool calling for agent workflows.
Which has the bigger context window?
GPT-5.1 and GPT-5.3 Codex have the largest context windows (400,000 and 400,000 tokens), against 262,144 for Qwen3.6 Max Preview. Maximum output per response: GPT-5.1 up to 128,000, GPT-5.3 Codex up to 128,000, Qwen3.6 Max Preview up to 65,536 tokens.
Which can read images, PDFs, audio or video?
GPT-5.1 accepts text and images; GPT-5.3 Codex accepts text, images and PDFs; Qwen3.6 Max Preview accepts text. GPT-5.3 Codex handles the widest range of inputs.
Are any of these open source?
No. GPT-5.1, GPT-5.3 Codex and Qwen3.6 Max Preview are proprietary and only available through APIs and apps.
Which is newer?
Qwen3.6 Max Preview is the newest, released Apr 20, 2026. GPT-5.3 Codex came out Feb 5, 2026; GPT-5.1 came out Nov 13, 2025. Knowledge cutoff: GPT-5.1 Sep 30, 2024, GPT-5.3 Codex Aug 31, 2025, Qwen3.6 Max Preview Apr 2025.
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.
