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DeepSeek V3.1 vs GPT-5-Codex

DeepSeek DeepSeek V3.1 vs OpenAI GPT-5-Codex — side-by-side specs.

DeepSeek
DeepSeek V3.1
OpenAI
GPT-5-Codex
Overview
CompanyDeepSeekOpenAI
Release dateAug 21 2025Sep 15 2025
Model type
Open sourceYesNo
Specifications
Parameters
Context window
Benchmarks
Timeline
Release gapDeepSeek V3.1 shipped 25 days before GPT-5-Codex

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

DeepSeek V3.1 and GPT-5-Codex don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. DeepSeek V3.1 shipped 25 days before GPT-5-Codex, so benchmark comparisons should account for the intervening progress.

DeepSeek V3.1 is an open-source / open-weight model; GPT-5-Codex is proprietary.

Direct benchmark comparisons are unavailable — DeepSeek V3.1 and GPT-5-Codex don't publish scores on any of the same benchmarks.

Frequently asked questions

When was DeepSeek V3.1 released?
DeepSeek V3.1 was released by DeepSeek on Aug 21 2025.
When was GPT-5-Codex released?
GPT-5-Codex was released by OpenAI on Sep 15 2025.
Is DeepSeek V3.1 or GPT-5-Codex open source?
DeepSeek V3.1 is an open-source / open-weight model released by DeepSeek. GPT-5-Codex is a proprietary model released by OpenAI.

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