DeepSeek-V4-Flash-0731 vs GPT-5.1 Codex High: Specs & Benchmark Comparison

DeepSeek-V4-Flash-0731 is developed by DeepSeek, while GPT-5.1 Codex High comes from OpenAI. GPT-5.1 Codex High was released in November 2025, and DeepSeek-V4-Flash-0731 followed 8 months later in July 2026. DeepSeek-V4-Flash-0731 has a published size of about 304 billion parameters; OpenAI has not disclosed the parameter count of GPT-5.1 Codex High.

We have 9 benchmark results for DeepSeek-V4-Flash-0731 and 1 benchmark result for GPT-5.1 Codex High, but they were measured on different benchmarks, so there is no like-for-like scoreboard.

DeepSeek-V4-Flash-0731 is the cheaper API at $0.14 per million input tokens and $0.28 per million output tokens, roughly 9 times cheaper than GPT-5.1 Codex High at $1.25 and $10. DeepSeek-V4-Flash-0731 takes the larger context window at 1M tokens, compared with 400K for GPT-5.1 Codex High. DeepSeek-V4-Flash-0731 accepts text as input, while GPT-5.1 Codex High accepts text and images.

CharacteristicDeepSeek-V4-Flash-0731GPT-5.1 Codex High
CompanyDeepSeekOpenAI
Release DateJuly 31, 2026November 11, 2025
Parameters304B
MultimodalNoYes
Context (input)1.0M400K
Context (output)393K128K
Input Price / 1M$0.14$1.25
Output Price / 1M$0.28$10.00
Average Score57.5%97.0%

Verdict

DeepSeek-V4-Flash-0731 leads in 3 out of 4 comparison categories.

Overall Performance

Both models show comparable average scores: DeepSeek-V4-Flash-0731 — 0.6, GPT-5.1 Codex High — 1.0.

API Cost

DeepSeek-V4-Flash-0731 is 26.8x cheaper: input $0.14/1M vs $1.25/1M tokens.

Context Window

DeepSeek-V4-Flash-0731 supports a larger context: 1M vs 400K tokens.

Recency

DeepSeek-V4-Flash-0731 is newer: released 7/31/2026 vs 11/11/2025.

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Frequently Asked Questions

Which is better for coding — DeepSeek-V4-Flash-0731 or GPT-5.1 Codex High?
Direct comparison on the SWE-Bench benchmark is not available. We recommend reviewing other metrics on the comparison page.
Which model is cheaper — DeepSeek-V4-Flash-0731 or GPT-5.1 Codex High?
DeepSeek-V4-Flash-0731 is cheaper for input: $0.14 per 1M tokens vs $1.25.
Which has a larger context window — DeepSeek-V4-Flash-0731 or GPT-5.1 Codex High?
DeepSeek-V4-Flash-0731 supports a larger context: 1,000,000 tokens vs 400,000.

The DeepSeek-V4-Flash-0731 and GPT-5.1 Codex High comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the DeepSeek-V4-Flash-0731 or GPT-5.1 Codex High page. See also the complete list of AI model comparisons.