Google: Gemini 3.7 Flash (batch) vs OpenAI: GPT-5.6 Luna
Side-by-side comparison of specs, pricing, benchmark scores, and task rankings. Updated 2026-09-28.
| Google: Gemini 3.7 Flash (batch) | OpenAI: GPT-5.6 Luna | |
|---|---|---|
| Vendor | openai | |
| Quality Score | 100 | 100 |
| Benchmark Score | 65.5 | 62.3 |
| Input Price | $0.38/M | $0.20/M |
| Output Price | $1.88/M | $1.20/M |
| Context Window | 1,048,576 | 1,050,000 |
| Max Output | 65,536 | 128,000 |
| Tool Calling | ✓ | ✓ |
| Structured Output | ✓ | ✓ |
| Reasoning Mode | ✓ | ✓ |
| Vision | ✓ | ✓ |
| Audio | ✓ | - |
| Benchmark Scores | ||
| ai_index | 64.4 | 61.6 |
The verdict
For a sample job of 1 million input tokens and 250,000 output tokens, GPT-5.6 Luna costs $0.50 and Gemini 3.7 Flash (batch) costs $0.84, so GPT-5.6 Luna is about 1.7 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 3.7 Flash (batch) offers audio input and video input.
On our blended benchmark score Gemini 3.7 Flash (batch) leads 65.5 to 62.3.
Across the 18 tasks where they differ, Gemini 3.7 Flash (batch) scores higher on 15 (SQL Generation, Code Review, Code Refactoring and others), GPT-5.6 Luna on 3 (Code Completion, JSON Extraction, Bulk Data Labeling).
Gemini 3.7 Flash (batch) was released in August 2026 and GPT-5.6 Luna in July 2026.
Pick Gemini 3.7 Flash (batch) if you need audio input, video input, benchmark performance or the stronger all-round task scores; pick GPT-5.6 Luna 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 3.7 Flash (batch) | OpenAI: GPT-5.6 Luna |
|---|---|---|
| SQL Generation | 141 | 141 |
| Code Review | 144 | 143 |
| Code Completion | 132 | 133 |
| Code Refactoring | 146 | 145 |
| Bug Fixing | 148 | 147 |
| Unit Test Generation | 131 | 131 |
| Regex Writing | 126 | 125 |
| CI/CD Pipelines | 127 | 127 |
| Frontend Component Design | 129 | 129 |
| Data Analysis | 133 | 133 |
| CSV / Spreadsheet Cleanup | 136 | 136 |
| ETL Scripting | 137 | 136 |
| JSON Extraction | 131 | 131 |
| Bulk Data Labeling | 129 | 129 |
| OCR / Document Parsing | 134 | 134 |
| Table Extraction from PDFs | 134 | 134 |
| Long-Document Summarization | 148 | 147 |
| Blog Post Writing | 129 | 129 |
Scores reflect capability match + benchmark data + pricing for each task. Methodology →