GPT-5.1 Codex vs Qwen3.5-397B-A17B
GPT-5.1 Codex and Qwen3.5-397B-A17B are closely matched at 29.6 and 38.8 on the LLM Stats Score. Qwen3.5-397B-A17B is 3.2x cheaper per token.
OpenAI · Alibaba Cloud / Qwen Team · Updated for 2026
Which is better?
GPT-5.1 Codex and Qwen3.5-397B-A17B are closely matched on the overall LLM Stats Score at 29.6 and 38.8.
The models split the 2 individual benchmarks reported for both models evenly.
On price, Qwen3.5-397B-A17B is roughly 3.2x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
GPT-5.1 Codex also accepts a larger context window (400,000 input tokens), making it the stronger choice for long documents and large codebases.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose GPT-5.1 Codex
- you process long inputs — it offers a 400,000 token context window
Choose Qwen3.5-397B-A17B
- cost matters — it's about 3.2x cheaper per token
- you want the most recent training data — it shipped Feb 2026
- you need open weights you can self-host or fine-tune
At a glance
The differences that matter most.
Individual benchmarks
3 reported for GPT-5.1 Codex · 38 for Qwen3.5-397B-A17B
GPT-5.1 Codex outperforms in 1 benchmarks (Terminal-Bench 2.0), while Qwen3.5-397B-A17B is better at 1 benchmark (SWE-Bench Verified).
Both models are evenly matched across the benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-5.1 Codex ($1.25/1M tokens) is 2.8x more expensive than Qwen3.5-397B-A17B ($0.45/1M tokens).
For output processing, GPT-5.1 Codex ($10.00/1M tokens) is 3.3x more expensive than Qwen3.5-397B-A17B ($3.00/1M tokens).
In conclusion, GPT-5.1 Codex is more expensive than Qwen3.5-397B-A17B.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GPT-5.1 Codex accepts 400,000 input tokens compared to Qwen3.5-397B-A17B's 262,144 tokens. Qwen3.5-397B-A17B can generate longer responses up to 262,144 tokens, while GPT-5.1 Codex is limited to 128,000 tokens.
Input capabilities
Documented input modalities across available providers
Both GPT-5.1 Codex and Qwen3.5-397B-A17B support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
GPT-5.1 Codex
Qwen3.5-397B-A17B
License
Usage and distribution terms
GPT-5.1 Codex is licensed under a proprietary license, while Qwen3.5-397B-A17B uses Apache 2.0.
License differences may affect how you can use these models in commercial or open-source projects.
Proprietary
Closed source
Apache 2.0
Open weights
Release Timeline
When each model was launched
GPT-5.1 Codex was released on 2025-11-19, while Qwen3.5-397B-A17B was released on 2026-02-16.
Qwen3.5-397B-A17B is 3 months newer than GPT-5.1 Codex.
Nov 19, 2025
9 months ago
Feb 16, 2026
6 months ago
2mo newerKnowledge Cutoff
When training data ends
GPT-5.1 Codex has a documented knowledge cutoff of 2024-09-30, while Qwen3.5-397B-A17B's cutoff date is not specified.
We can confirm GPT-5.1 Codex's training data extends to 2024-09-30, but cannot make a direct comparison without Qwen3.5-397B-A17B's cutoff date.
Sep 2024
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Provider Availability
GPT-5.1 Codex is available from OpenAI. Qwen3.5-397B-A17B is available from DeepInfra, Novita.
GPT-5.1 Codex
Qwen3.5-397B-A17B
Outputs Comparison
Judge for yourself.
Run your own prompts against GPT-5.1 Codex and Qwen3.5-397B-A17B side-by-side, then vote on the output you prefer.
FAQ
Common questions about GPT-5.1 Codex vs Qwen3.5-397B-A17B.