GPT-5.1 ChatvsGPT-5.1-Codex
GPT-5.1-Codex has a larger context window than GPT-5.1 Chat (400K tokens vs 128K tokens).
| Spec | GPT-5.1 Chat | GPT-5.1-Codex |
|---|---|---|
| Input price | $1.25/M tokens | $1.25/M tokens |
| Output price | $10/M tokens | $10/M tokens |
| Context window | 128K tokens | 400K tokens |
| Released | Nov 2025 | Nov 2025 |
| SWE-bench Verified | 76.3% | 73.7% |
Our Verdict
GPT-5.1-Codex
GPT-5.1 ChatRunner-up
Not enough votes to call it. On the specs, GPT-5.1-Codex has the edge: bigger model tier, bigger context window.
Too close to call
API pricing
Cost per 1M tokens
GPT-5.1 Chat
Input
$1.25
Output
$10.00
GPT-5.1-Codex
Input
$1.25
Output
$10.00
Writing DNA
Style Comparison
Similarity
71%
GPT-5.1-Codex uses 50.1x more headings
GPT-5.1 Chat
GPT-5.1-Codex
73%Vocabulary70%
18wSentence Length17w
0.45Hedging0.39
1.1Bold3.4
2.4Lists3.5
0.00Emoji0.00
0.00Headings0.50
0.06Transitions0.38
Based on 15 + 14 text responses
Research
What we learned reading every model
FAQ
Common questions
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