OpenAI: GPT-6 Luna vs DeepSeek: DeepSeek V4.1 Flash
Side-by-side comparison of specs, pricing, benchmark scores, and task rankings. Updated 2026-10-13.
| OpenAI: GPT-6 Luna | DeepSeek: DeepSeek V4.1 Flash | |
|---|---|---|
| Vendor | openai | deepseek |
| Quality Score | 100 | 100 |
| Benchmark Score | 63.8 | 66.3 |
| Input Price | $0.10/M | $0.15/M |
| Output Price | $0.50/M | $0.60/M |
| Context Window | 1,050,000 | 1,048,576 |
| Max Output | 128,000 | 393,216 |
| Tool Calling | ✓ | ✓ |
| Structured Output | ✓ | ✓ |
| Reasoning Mode | ✓ | ✓ |
| Vision | ✓ | ✓ |
| Audio | - | - |
| Benchmark Scores | ||
| ai_index | 62.9 | 65.1 |
The verdict
For a sample job of 1 million input tokens and 250,000 output tokens, GPT-6 Luna costs $0.23 and DeepSeek V4.1 Flash costs $0.30, so GPT-6 Luna is about 1.3 times cheaper for the same work.
Both take in a similar amount of text: 1,050,000 and 1,048,576 tokens, about 1,575 and 1,573 pages.
On our blended benchmark score DeepSeek V4.1 Flash leads 66.3 to 63.8.
Across the 18 tasks where they differ, GPT-6 Luna scores higher on 1 (JSON Extraction), DeepSeek V4.1 Flash on 17 (SQL Generation, Code Review, Code Completion and others).
Pick GPT-6 Luna if you need lower cost; pick DeepSeek V4.1 Flash if you need benchmark performance 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 | OpenAI: GPT-6 Luna | DeepSeek: DeepSeek V4.1 Flash |
|---|---|---|
| SQL Generation | 141 | 141 |
| Code Review | 144 | 144 |
| Code Completion | 133 | 133 |
| Code Refactoring | 146 | 146 |
| Bug Fixing | 148 | 148 |
| Unit Test Generation | 131 | 131 |
| Code Documentation | 137 | 137 |
| Regex Writing | 126 | 126 |
| CI/CD Pipelines | 127 | 127 |
| Frontend Component Design | 129 | 129 |
| Data Analysis | 133 | 133 |
| ETL Scripting | 136 | 137 |
| JSON Extraction | 131 | 131 |
| OCR / Document Parsing | 134 | 134 |
| Table Extraction from PDFs | 134 | 134 |
| Long-Document Summarization | 148 | 148 |
| Short-Form Summarization | 127 | 127 |
| Blog Post Writing | 129 | 129 |
Scores reflect capability match + benchmark data + pricing for each task. Methodology →