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DeepSeek V3.1 Terminus vs GPT-5-Codex

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

DeepSeek
DeepSeek V3.1 Terminus
OpenAI
GPT-5-Codex
Overview
CompanyDeepSeekOpenAI
Release dateSep 22 2025Sep 15 2025
Model type
Open sourceYesNo
Specifications
Parameters
Context window
Benchmarks
Timeline
Release gapGPT-5-Codex shipped 7 days before DeepSeek V3.1 Terminus

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

DeepSeek V3.1 Terminus and GPT-5-Codex don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. GPT-5-Codex shipped 7 days before DeepSeek V3.1 Terminus, so benchmark comparisons should account for the intervening progress.

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

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

Frequently asked questions

When was DeepSeek V3.1 Terminus released?
DeepSeek V3.1 Terminus was released by DeepSeek on Sep 22 2025.
When was GPT-5-Codex released?
GPT-5-Codex was released by OpenAI on Sep 15 2025.
Is DeepSeek V3.1 Terminus or GPT-5-Codex open source?
DeepSeek V3.1 Terminus is an open-source / open-weight model released by DeepSeek. GPT-5-Codex is a proprietary model released by OpenAI.

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