Google: Gemini 4 Argon vs OpenAI: GPT-6 Luna Pro
Side-by-side comparison of specs, pricing, benchmark scores, and task rankings. Updated 2026-10-19.
| Google: Gemini 4 Argon | OpenAI: GPT-6 Luna Pro | |
|---|---|---|
| Vendor | openai | |
| Quality Score | 100 | 100 |
| Benchmark Score | 90.2 | - |
| Input Price | $2.00/M | $0.10/M |
| Output Price | $10.00/M | $0.50/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 | 86.7 | - |
The verdict
For a sample job of 1 million input tokens and 250,000 output tokens, GPT-6 Luna Pro costs $0.23 and Gemini 4 Argon costs $4.50, so GPT-6 Luna Pro is about 20.0 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.
Only Gemini 4 Argon offers audio input and video input.
Across the 20 tasks where they differ, Gemini 4 Argon scores higher on 16 (SQL Generation, Code Review, Code Refactoring and others), GPT-6 Luna Pro on 4 (Code Completion, JSON Extraction, Bulk Data Labeling and others).
Gemini 4 Argon was released in October 2026 and GPT-6 Luna Pro in September 2026.
Pick Gemini 4 Argon if you need audio input, video input or the stronger all-round task scores; pick GPT-6 Luna Pro if you need lower cost.
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 | Google: Gemini 4 Argon | OpenAI: GPT-6 Luna Pro |
|---|---|---|
| SQL Generation | 143 | 133 |
| Code Review | 148 | 132 |
| Code Completion | 119 | 131 |
| Code Refactoring | 149 | 136 |
| Bug Fixing | 152 | 136 |
| Unit Test Generation | 134 | 124 |
| Code Documentation | 137 | 131 |
| Regex Writing | 126 | 119 |
| CI/CD Pipelines | 130 | 120 |
| Frontend Component Design | 132 | 122 |
| Data Analysis | 137 | 124 |
| CSV / Spreadsheet Cleanup | 136 | 133 |
| ETL Scripting | 140 | 128 |
| JSON Extraction | 121 | 131 |
| Bulk Data Labeling | 118 | 129 |
| OCR / Document Parsing | 135 | 131 |
| Table Extraction from PDFs | 135 | 131 |
| Long-Document Summarization | 150 | 137 |
| Short-Form Summarization | 117 | 123 |
| Blog Post Writing | 131 | 121 |
Scores reflect capability match + benchmark data + pricing for each task. Methodology →