GPT-4 vs o1

Compare GPT-4 and o1, both from OpenAI, context windows of 8K vs 128K, tested across 21 shared challenges. Updated April 2026.

Which is better, GPT-4 or o1?

GPT-4 and o1 are both competitive models. GPT-4 costs $30/M input tokens vs $15/M for o1. Context windows: 8K vs 128K tokens. Compare their real outputs side by side below.

Key Differences Between GPT-4 and o1

GPT-4 is made by openai while o1 is from openai. GPT-4 has a 8K token context window compared to o1's 128K. On pricing, GPT-4 costs $30/M input tokens vs $15/M for o1.

Our Verdict
GPT-4
GPT-4
o1
o1

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
Writing DNA

Style Comparison

Similarity
98%

o1 uses 43.7x more headings

GPT-4
o1
59%Vocabulary64%
18wSentence Length16w
1.10Hedging0.76
0.8Bold5.0
2.5Lists2.6
0.00Emoji0.00
0.00Headings0.44
0.45Transitions0.40
Based on 15 + 13 text responses
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Ask them anything yourself

GPT-4o1

279 AI models invented the same fake scientist.

We read every word. 250 models. 2.14 million words. This is what we found.

AI Hallucination Index 2026
Free preview13 of 58 slides
FAQ

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