DeepSeek: DeepSeek V4.1 Flash vs OpenAI: GPT-5.6 Luna Pro
Side-by-side comparison of specs, pricing, benchmark scores, and task rankings. Updated 2026-11-07.
| DeepSeek: DeepSeek V4.1 Flash | OpenAI: GPT-5.6 Luna Pro | |
|---|---|---|
| Vendor | deepseek | openai |
| Quality Score | 100 | 100 |
| Input Price | $0.05/M | $0.20/M |
| Output Price | $0.57/M | $1.20/M |
| Context Window | 1,048,576 | 1,050,000 |
| Max Output | 943,718 | 128,000 |
| Tool Calling | ✓ | ✓ |
| Structured Output | ✓ | ✓ |
| Reasoning Mode | ✓ | ✓ |
| Vision | ✓ | ✓ |
| Audio | - | - |
The verdict
For a sample job of 1 million input tokens and 250,000 output tokens, DeepSeek V4.1 Flash costs $0.19 and GPT-5.6 Luna Pro costs $0.50, so DeepSeek V4.1 Flash is about 2.6 times cheaper for the same work.
Both take in a similar amount of text: 1,048,576 and 1,050,000 tokens, about 1,573 and 1,575 pages.
Across the 6 tasks where they differ, DeepSeek V4.1 Flash scores higher on 6 (Code Completion, Code Documentation, Regex Writing and others).
DeepSeek V4.1 Flash was released in September 2026 and GPT-5.6 Luna Pro in July 2026.
Pick DeepSeek V4.1 Flash if you need lower cost or the stronger all-round task scores.
Costs use current list prices per million tokens; page counts assume about 0.75 words per token and 500 words per page.
Who wins by task?
| Task | DeepSeek: DeepSeek V4.1 Flash | OpenAI: GPT-5.6 Luna Pro |
|---|---|---|
| Code Completion | 131 | 131 |
| Code Documentation | 131 | 131 |
| Regex Writing | 119 | 119 |
| JSON Extraction | 131 | 131 |
| Bulk Data Labeling | 129 | 129 |
| Short-Form Summarization | 123 | 123 |
Scores reflect capability match + benchmark data + pricing for each task. Methodology →