GPT-5 Pro vs Mistral Medium 3

Compare GPT-5 Pro by OpenAI against Mistral Medium 3 by Mistral AI, context windows of 400K vs 131K, tested across 21 shared challenges. Updated April 2026.

Which is better, GPT-5 Pro or Mistral Medium 3?

GPT-5 Pro and Mistral Medium 3 are both competitive models. GPT-5 Pro costs $15/M input tokens vs $0.4/M for Mistral Medium 3. Context windows: 400K vs 131K tokens. Compare their real outputs side by side below.

Key Differences Between GPT-5 Pro and Mistral Medium 3

GPT-5 Pro is made by openai while Mistral Medium 3 is from mistral. GPT-5 Pro has a 400K token context window compared to Mistral Medium 3's 131K. On pricing, GPT-5 Pro costs $15/M input tokens vs $0.4/M for Mistral Medium 3.

Our Verdict
GPT-5 Pro
GPT-5 Pro
Mistral Medium 3
Mistral Medium 3Runner-up

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

Mistral Medium 3 is 60x cheaper per token — worth considering if cost matters.

Slight edge
Writing DNA

Style Comparison

Similarity
98%

Mistral Medium 3 uses 859.1x more bold

GPT-5 Pro
Mistral Medium 3
65%Vocabulary57%
15wSentence Length17w
0.32Hedging0.73
0.0Bold8.6
2.9Lists6.5
0.00Emoji0.06
0.00Headings1.18
0.01Transitions0.15
Based on 11 + 15 text responses
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GPT-5 ProMistral Medium 3

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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