AiGanakGPT-6 Luna vs Gemini 3.5 Flash-Lite: API pricing
GPT-6 Luna is cheaper: a typical support answer costs $0.00049 against $0.00197 on Gemini 3.5 Flash-Lite at list prices checked 26 October 2026.
GPT-6 Luna: $0.1 input / $0.5 output per 1M tokens. Gemini 3.5 Flash-Lite: $0.3 / $2.50.
Prices side by side
Sources: OpenAI, Google, checked 26 October 2026. Full details: GPT-6 Luna · Gemini 3.5 Flash-Lite.
| GPT-6 Luna | Gemini 3.5 Flash-Lite | |
|---|---|---|
| Input | $0.1 | $0.3 |
| Cached input | $0.01 | $0.03 |
| Output | $0.5 | $2.50 |
| Batch input / output | $0.05 / $0.25 | $0.15 / $1.25 |
| Cache write | $0.125 | not charged separately |
| Long prompts | Prompts over 272K input tokens cost 2x input and cache rates and 1.5x output for the whole request. | No long-prompt surcharge listed |
| Announced change | None announced | None announced |
Cost per request
Token counts are stated so you can check the arithmetic.
| Task | Tokens | GPT-6 Luna | Gemini 3.5 Flash-Lite |
|---|---|---|---|
| Chat reply | 2,000 input tokens, none cached, 300-token reply | $0.00035 | $0.00135 |
| Support answer | 6,000 input tokens (4,000 cached instructions and help text), 500-token answer | $0.00049 | $0.00197 |
| Document summary | 20,000-token document, no caching, 800-token summary | $0.00240 | $0.00800 |
Monthly cost of support answers
| Answers per month | GPT-6 Luna | Gemini 3.5 Flash-Lite | Difference |
|---|---|---|---|
| 10,000 | $4.90 | $19.70 | $14.80 |
| 100,000 | $49.00 | $197 | $148 |
| 1,000,000 | $490 | $1,970 | $1,480 |
Price per token is only part of the story: the model that answers in fewer tokens, or needs fewer retries, can be cheaper in practice. Test both on your own requests before switching.
GPT-6 Luna vs Gemini 3.5 Flash-Lite: pricing questions
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Is GPT-6 Luna cheaper than Gemini 3.5 Flash-Lite?
GPT-6 Luna is cheaper: a typical support answer costs $0.00049 against $0.00197 on Gemini 3.5 Flash-Lite at list prices checked 26 October 2026.
How much more does Gemini 3.5 Flash-Lite cost than GPT-6 Luna?
For a support answer with 6,000 input tokens (4,000 cached) and a 500-token reply, Gemini 3.5 Flash-Lite costs 4.0× more than GPT-6 Luna: $1.97 against $0.490 per 1,000 answers.
What do GPT-6 Luna and Gemini 3.5 Flash-Lite cost with batch processing?
Batch prices per million tokens: GPT-6 Luna $0.05 input / $0.25 output, Gemini 3.5 Flash-Lite $0.15 / $1.25. Batch requests return within 24 hours.
Should I switch from GPT-6 Luna to Gemini 3.5 Flash-Lite?
Only if quality holds on your own examples. Price per token is one factor; how many tokens each model uses for your task, and how often its answers need a retry, decide the real cost. Test both on 50 to 100 real requests before switching.
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