GPT-4o (Omni) vs GPT-5 Pro

Compare GPT-4o (Omni) and GPT-5 Pro, both from OpenAI, context windows of 128K vs 400K, tested across 42 shared challenges. Updated April 2026.

Which is better, GPT-4o (Omni) or GPT-5 Pro?

GPT-4o (Omni) and GPT-5 Pro are both competitive models. GPT-4o (Omni) costs $2.5/M input tokens vs $15/M for GPT-5 Pro. Context windows: 128K vs 400K tokens. Compare their real outputs side by side below.

Key Differences Between GPT-4o (Omni) and GPT-5 Pro

GPT-4o (Omni) is made by openai while GPT-5 Pro is from openai. GPT-4o (Omni) has a 128K token context window compared to GPT-5 Pro's 400K. On pricing, GPT-4o (Omni) costs $2.5/M input tokens vs $15/M for GPT-5 Pro.

Our Verdict
GPT-5 Pro
GPT-5 Pro
GPT-4o (Omni)
GPT-4o (Omni)Runner-up

No community votes yet. On paper, GPT-5 Pro has the edge — newer, bigger context window.

GPT-4o (Omni) is 12x cheaper per token — worth considering if cost matters.

Too close to call
Writing DNA

Style Comparison

Similarity
93%

GPT-4o (Omni) uses 734.5x more bold

GPT-4o (Omni)
GPT-5 Pro
54%Vocabulary65%
18wSentence Length15w
0.72Hedging0.32
7.3Bold0.0
5.6Lists2.9
0.03Emoji0.00
1.40Headings0.00
0.26Transitions0.01
Based on 24 + 11 text responses
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GPT-4o (Omni)GPT-5 Pro

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
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