DeepSeek: DeepSeek V4.1 Flash vs OpenAI: GPT-5.6 Luna (batch)
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 (batch) | |
|---|---|---|
| Vendor | deepseek | openai |
| Quality Score | 100 | 100 |
| Benchmark Score | - | 89.4 |
| Input Price | $0.05/M | $0.10/M |
| Output Price | $0.57/M | $0.60/M |
| Context Window | 1,048,576 | 1,050,000 |
| Max Output | 943,718 | 128,000 |
| Tool Calling | ✓ | ✓ |
| Structured Output | ✓ | ✓ |
| Reasoning Mode | ✓ | ✓ |
| Vision | ✓ | ✓ |
| Audio | - | - |
| Benchmark Scores | ||
| ai_index | - | 84.5 |
| ai_index_agentic | - | 75.2 |
| ai_index_coding | - | 100.0 |
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 (batch) costs $0.25, so DeepSeek V4.1 Flash is about 1.3 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 20 tasks where they differ, GPT-5.6 Luna (batch) on 20 (SQL Generation, Code Review, Code Completion and others).
DeepSeek V4.1 Flash was released in September 2026 and GPT-5.6 Luna (batch) in July 2026.
Pick DeepSeek V4.1 Flash if you need lower cost; pick GPT-5.6 Luna (batch) if you need 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 (batch) |
|---|---|---|
| SQL Generation | 133 | 171 |
| Code Review | 132 | 166 |
| Code Completion | 131 | 133 |
| Code Refactoring | 136 | 163 |
| Bug Fixing | 136 | 179 |
| Unit Test Generation | 124 | 154 |
| Code Documentation | 131 | 143 |
| Regex Writing | 119 | 136 |
| CI/CD Pipelines | 120 | 144 |
| Frontend Component Design | 122 | 146 |
| Data Analysis | 124 | 170 |
| CSV / Spreadsheet Cleanup | 133 | 154 |
| ETL Scripting | 128 | 154 |
| JSON Extraction | 131 | 149 |
| Bulk Data Labeling | 129 | 135 |
| OCR / Document Parsing | 131 | 146 |
| Table Extraction from PDFs | 131 | 146 |
| Long-Document Summarization | 137 | 160 |
| Short-Form Summarization | 123 | 132 |
| Blog Post Writing | 121 | 140 |
Scores reflect capability match + benchmark data + pricing for each task. Methodology →