OpenAI: GPT-5.6 Luna Pro vs Google: Gemini 3.1 Flash Lite (batch)
Side-by-side comparison of specs, pricing, benchmark scores, and task rankings. Updated 2026-11-07.
| OpenAI: GPT-5.6 Luna Pro | Google: Gemini 3.1 Flash Lite (batch) | |
|---|---|---|
| Vendor | openai | |
| Quality Score | 100 | 100 |
| Input Price | $0.20/M | $0.12/M |
| Output Price | $1.20/M | $0.75/M |
| Context Window | 1,050,000 | 1,048,576 |
| Max Output | 128,000 | 65,536 |
| Tool Calling | ✓ | ✓ |
| Structured Output | ✓ | ✓ |
| Reasoning Mode | ✓ | ✓ |
| Vision | ✓ | ✓ |
| Audio | - | ✓ |
The verdict
For a sample job of 1 million input tokens and 250,000 output tokens, Gemini 3.1 Flash Lite (batch) costs $0.31 and GPT-5.6 Luna Pro costs $0.50, so Gemini 3.1 Flash Lite (batch) is about 1.6 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.
Only Gemini 3.1 Flash Lite (batch) offers audio input and video input.
Across the 6 tasks where they differ, Gemini 3.1 Flash Lite (batch) on 6 (Code Completion, Code Documentation, Regex Writing and others).
GPT-5.6 Luna Pro was released in July 2026 and Gemini 3.1 Flash Lite (batch) in May 2026.
Pick Gemini 3.1 Flash Lite (batch) if you need lower cost, audio input, video input 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-5.6 Luna Pro | Google: Gemini 3.1 Flash Lite (batch) |
|---|---|---|
| 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 →