DeepSeek-V4-Flash-0731 vs GPT-5.6 Luna: Specs & Benchmark Comparison
DeepSeek-V4-Flash-0731 is developed by DeepSeek, while GPT-5.6 Luna comes from OpenAI. Both were released 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-5.6 Luna.
The two models share 5 published benchmarks. GPT-5.6 Luna leads on 3 of them, DeepSeek-V4-Flash-0731 on 2. The widest gaps are on Agents' Last Exam, where GPT-5.6 Luna scores 50.3% against 25.2%; Toolathlon, where DeepSeek-V4-Flash-0731 scores 70.0% against 53.4%. Averaged across everything we track, DeepSeek-V4-Flash-0731 sits at 57.5% and GPT-5.6 Luna at 51.5%.
DeepSeek-V4-Flash-0731 is the cheaper API at $0.14 per million input tokens and $0.28 per million output tokens, about 43% below GPT-5.6 Luna at $0.20 and $1.20. Both accept a context window of about 1M tokens. DeepSeek-V4-Flash-0731 accepts text as input, while GPT-5.6 Luna accepts text and images.
| Characteristic | DeepSeek-V4-Flash-0731 | GPT-5.6 Luna |
|---|---|---|
| Company | DeepSeek | OpenAI |
| Release Date | July 31, 2026 | July 9, 2026 |
| Parameters | 304B | — |
| Multimodal | No | Yes |
| Context (input) | 1.0M | 1.1M |
| Context (output) | 393K | 128K |
| Input Price / 1M | $0.14 | $0.20 |
| Output Price / 1M | $0.28 | $1.20 |
| Average Score | 57.5% | 51.5% |
| Benchmarks | ||
| Agents' Last Exam | 25.2% | 50.3% |
| Toolathlon | 70.0% | 53.4% |
| DeepSWE | 54.4% | 67.2% |
| AutomationBench | 25.1% | 14.9% |
| Terminal-Bench 2.1 | 83.0% | 84.7% |
Visual Benchmark Comparison
Verdict
DeepSeek-V4-Flash-0731 leads in 2 out of 4 comparison categories.
Both models show comparable average scores: DeepSeek-V4-Flash-0731 — 0.6, GPT-5.6 Luna — 0.5.
DeepSeek-V4-Flash-0731 is 3.3x cheaper: input $0.14/1M vs $0.20/1M tokens.
GPT-5.6 Luna supports a larger context: 1M vs 1M tokens.
DeepSeek-V4-Flash-0731 is newer: released 7/31/2026 vs 7/9/2026.
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Frequently Asked Questions
Which is better for coding — DeepSeek-V4-Flash-0731 or GPT-5.6 Luna?
Which model is cheaper — DeepSeek-V4-Flash-0731 or GPT-5.6 Luna?
Which has a larger context window — DeepSeek-V4-Flash-0731 or GPT-5.6 Luna?
The DeepSeek-V4-Flash-0731 and GPT-5.6 Luna 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-5.6 Luna page. See also the complete list of AI model comparisons.