GPT-5.1-Codex vs OpenAI: GPT-5.6 Terra
Compare GPT-5.1-Codex and OpenAI: GPT-5.6 Terra, both from OpenAI, context windows of 400K vs 1.1M, tested across 52 shared challenges.
Our Verdict
GPT-5.1-Codex
OpenAI: GPT-5.6 Terra
No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.
Too close to call
API pricing
Cost per 1M tokens
GPT-5.1-Codex
Input
$1.25
2.0× cheaper
Output
$10.00
1.5× cheaper
OpenAI: GPT-5.6 Terra
Input
$2.50
Output
$15.00
GPT-5.1-Codex is cheaper on both — 2.0× input, 1.5× output
Writing DNA
Style Comparison
Similarity
57%
GPT-5.1-Codex uses 6.8x more transitions
GPT-5.1-Codex
OpenAI: GPT-5.6 Terra
70%Vocabulary57%
17wSentence Length18w
0.39Hedging0.85
3.4Bold2.8
3.5Lists4.6
0.00Emoji0.00
0.50Headings1.12
0.38Transitions0.06
Based on 14 + 27 text responses
Research
What we learned reading every model
FAQ
