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DeepSeek-V4-Flash-0731 vs GPT-5 Codex

Comparing DeepSeek-V4-Flash-0731 and GPT-5 Codex across benchmarks, pricing, and capabilities.

DeepSeek · OpenAI · Updated for 2026

Which is better?

DeepSeek-V4-Flash-0731 and GPT-5 Codex trade strengths across price, capabilities, and technical limits. The better choice depends on the workload.

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

Choose DeepSeek-V4-Flash-0731

  • you want the most recent training data — it shipped Jul 2026
  • you need open weights you can self-host or fine-tune

Choose GPT-5 Codex

  • you are already invested in the OpenAI ecosystem

At a glance

The differences that matter most.

DeepSeek-V4-Flash-0731
DeepSeek
GPT-5 Codex
OpenAI
Benchmark wins
—
—
Input price
$0.09 / M
— / M
Output price
$0.18 / M
— / M
Context window
1,048,576
—
Released
Jul 2026
Sep 2025
License
MIT
Proprietary

Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

DeepSeek-V4-Flash-0731 and GPT-5 Codexdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Arena Performance

Playground indexes and blind preference scores

Context Window

Maximum input and output token capacity

Only DeepSeek-V4-Flash-0731 specifies input context (1,048,576 tokens). Only DeepSeek-V4-Flash-0731 specifies output context (65,536 tokens).

DeepSeek
DeepSeek-V4-Flash-0731
Input1,048,576 tokens
Output65,536 tokens
OpenAI
GPT-5 Codex
Input- tokens
Output- tokens
Tue Aug 25 2026 • llm-stats.com

License

Usage and distribution terms

DeepSeek-V4-Flash-0731 is licensed under MIT, 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-V4-Flash-0731

MIT

Open weights

GPT-5 Codex

Proprietary

Closed source

Release Timeline

When each model was launched

DeepSeek-V4-Flash-0731 was released on 2026-07-31, while GPT-5 Codex was released on 2025-09-15.

DeepSeek-V4-Flash-0731 is 11 months newer than GPT-5 Codex.

DeepSeek-V4-Flash-0731

Jul 31, 2026

3 weeks ago

10mo newer
GPT-5 Codex

Sep 15, 2025

11 months ago

Knowledge Cutoff

When training data ends

GPT-5 Codex has a documented knowledge cutoff of 2024-09-30, while DeepSeek-V4-Flash-0731'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-V4-Flash-0731's cutoff date.

DeepSeek-V4-Flash-0731

—

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-V4-Flash-0731 and GPT-5 Codex side-by-side, then vote on the output you prefer.

DeepSeek-V4-Flash-0731
✓ Preferred
GPT-5 Codex
Open in Playground

FAQ

Common questions about DeepSeek-V4-Flash-0731 vs GPT-5 Codex.

Which is better, DeepSeek-V4-Flash-0731 or GPT-5 Codex?

DeepSeek-V4-Flash-0731 (DeepSeek) and GPT-5 Codex (OpenAI) each have strengths in different areas. Compare their benchmark scores, pricing, context windows, and capabilities above to determine which fits your needs.

How does DeepSeek-V4-Flash-0731 compare to GPT-5 Codex in benchmarks?

DeepSeek-V4-Flash-0731 scores Terminal-Bench 2.1: 82.7%, CyberGym: 76.7%, Toolathlon: 70.3%, DSBench-FullStack: 68.7%, DSBench-Hard: 59.6%. GPT-5 Codex scores SWE-Bench Verified: 74.5%.

What are the context window sizes for DeepSeek-V4-Flash-0731 and GPT-5 Codex?

DeepSeek-V4-Flash-0731 supports 1.0M 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-V4-Flash-0731 and GPT-5 Codex?

Key differences include licensing (MIT vs Proprietary). See the full comparison above for benchmark-by-benchmark results.

Who makes DeepSeek-V4-Flash-0731 and GPT-5 Codex?

DeepSeek-V4-Flash-0731 is developed by DeepSeek and GPT-5 Codex is developed by OpenAI.

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