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DeepSeek-V3 vs GPT-5 Codex

GPT-5 Codex significantly outperforms across most benchmarks.

DeepSeek · OpenAI · Updated for 2026

Which is better?

DeepSeek-V3 outperforms in 0 benchmarks, while GPT-5 Codex is better at 1 benchmark (SWE-Bench Verified). GPT-5 Codex significantly outperforms across most benchmarks.

Based on current benchmark, pricing, and model metadata for 2026.

Choose DeepSeek-V3

  • you need open weights you can self-host or fine-tune

Choose GPT-5 Codex

  • you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
  • you want the most recent training data — it shipped Sep 2025

At a glance

The differences that matter most.

DeepSeek-V3
DeepSeek
GPT-5 Codex
OpenAI
Benchmark wins
0 of 1
1 of 1
Input price
$0.27 / M
— / M
Output price
$1.10 / M
— / M
Context window
131,072
—
Released
Dec 2024
Sep 2025
License
MIT + Model License (Commercial use allowed)
Proprietary

Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

DeepSeek-V3 outperforms in 0 benchmarks, while GPT-5 Codex is better at 1 benchmark (SWE-Bench Verified).

GPT-5 Codex significantly outperforms across most benchmarks.

Tue Aug 25 2026 • llm-stats.com

Arena Performance

Playground indexes and blind preference scores

Context Window

Maximum input and output token capacity

Only DeepSeek-V3 specifies input context (131,072 tokens). Only DeepSeek-V3 specifies output context (131,072 tokens).

DeepSeek
DeepSeek-V3
Input131,072 tokens
Output131,072 tokens
OpenAI
GPT-5 Codex
Input- tokens
Output- tokens
Tue Aug 25 2026 • llm-stats.com

License

Usage and distribution terms

DeepSeek-V3 is licensed under MIT + Model License (Commercial use allowed), while GPT-5 Codex uses a proprietary license.

License differences may affect how you can use these models in commercial or open-source projects.

DeepSeek-V3

MIT + Model License (Commercial use allowed)

Open weights

GPT-5 Codex

Proprietary

Closed source

Release Timeline

When each model was launched

DeepSeek-V3 was released on 2024-12-25, while GPT-5 Codex was released on 2025-09-15.

GPT-5 Codex is 9 months newer than DeepSeek-V3.

DeepSeek-V3

Dec 25, 2024

1.7 years ago

GPT-5 Codex

Sep 15, 2025

11 months ago

8mo newer

Knowledge Cutoff

When training data ends

GPT-5 Codex has a documented knowledge cutoff of 2024-09-30, while DeepSeek-V3's cutoff date is not specified.

We can confirm GPT-5 Codex's training data extends to 2024-09-30, but cannot make a direct comparison without DeepSeek-V3's cutoff date.

DeepSeek-V3

—

GPT-5 Codex

Sep 2024

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against DeepSeek-V3 and GPT-5 Codex side-by-side, then vote on the output you prefer.

DeepSeek-V3
✓ Preferred
GPT-5 Codex
Open in Playground

FAQ

Common questions about DeepSeek-V3 vs GPT-5 Codex.

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

GPT-5 Codex significantly outperforms across most benchmarks. DeepSeek-V3 is made by DeepSeek and GPT-5 Codex is made by OpenAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does DeepSeek-V3 compare to GPT-5 Codex in benchmarks?

DeepSeek-V3 scores DROP: 91.6%, CLUEWSC: 90.9%, MATH-500: 90.2%, MMLU-Redux: 89.1%, MMLU: 88.5%. GPT-5 Codex scores SWE-Bench Verified: 74.5%.

What are the context window sizes for DeepSeek-V3 and GPT-5 Codex?

DeepSeek-V3 supports 131K tokens and GPT-5 Codex supports an unknown number of tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between DeepSeek-V3 and GPT-5 Codex?

Key differences include licensing (MIT + Model License (Commercial use allowed) vs Proprietary). See the full comparison above for benchmark-by-benchmark results.

Who makes DeepSeek-V3 and GPT-5 Codex?

DeepSeek-V3 is developed by DeepSeek and GPT-5 Codex is developed by OpenAI.

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