GPT-4 vs GPT-5.1 Chat
Compare GPT-4 and GPT-5.1 Chat, both from OpenAI, context windows of 8K vs 128K, tested across 26 shared challenges.
Our Verdict
GPT-4
GPT-5.1 Chat
No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.
GPT-5.1 Chat is 6.0x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
GPT-4
Input
$30.00
Output
$60.00
GPT-5.1 Chat
Input
$1.25
24× cheaper
Output
$10.00
6.0× cheaper
GPT-5.1 Chat is cheaper on both — 24× input, 6.0× output
Writing DNA
Style Comparison
Similarity
48%
GPT-4 uses 7.8x more transitions
GPT-4
GPT-5.1 Chat
59%Vocabulary73%
18wSentence Length18w
1.10Hedging0.45
0.8Bold1.1
2.5Lists2.4
0.00Emoji0.00
0.00Headings0.00
0.45Transitions0.06
Based on 15 + 15 text responses
Research
What we learned reading every model
FAQ
Common questions
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