DeepSeek V3.1 vs GPT-5 Codex

Compare DeepSeek V3.1 by DeepSeek against GPT-5 Codex by OpenAI, tested across 50 shared challenges. Updated April 2026.

Which is better, DeepSeek V3.1 or GPT-5 Codex?

DeepSeek V3.1 and GPT-5 Codex are both competitive models. Compare their real outputs side by side below.

Key Differences Between DeepSeek V3.1 and GPT-5 Codex

DeepSeek V3.1 is made by deepseek while GPT-5 Codex is from openai.

Our Verdict
DeepSeek V3.1
DeepSeek V3.1
GPT-5 Codex
GPT-5 Codex

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
100%

GPT-5 Codex uses 6.2x more emoji

DeepSeek V3.1
GPT-5 Codex
53%Vocabulary64%
14wSentence Length17w
0.42Hedging0.38
4.0Bold2.3
3.6Lists3.5
0.02Emoji0.15
0.40Headings0.49
0.22Transitions0.05
Based on 23 + 13 text responses
vs

Ask them anything yourself

DeepSeek V3.1GPT-5 Codex

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

Common questions