High-volume, cost-sensitive work
Choose Gemini 2.5 Flash-Lite
Gemini 2.5 Flash-Lite costs 13% less on a typical mix of three input tokens for every output token ($0.18 against $0.20 per million tokens).
Gemini 2.5 Flash-Lite vs GPT-6 Luna Pro: price, context and capabilities
Choose Gemini 2.5 Flash-Lite for high-volume, cost-sensitive work and writing and code generation. Choose GPT-6 Luna Pro for the latest release.
In short
- Gemini 2.5 Flash-Lite is 13% cheaper than GPT-6 Luna Pro at the headline price ($0.175 / 1M tokens vs $0.20 / 1M tokens).
- GPT-6 Luna Pro reads more per request: 1.05M tokens against 1.05M.
- GPT-6 Luna Pro is the newer model (Sep 22, 2026, against July 2025).
- Only Gemini 2.5 Flash-Lite offers batch api.
Which should you choose?
Each answer below comes straight from the published prices, specifications and independent benchmark results.
Writing and code generation
Choose Gemini 2.5 Flash-Lite
Gemini 2.5 Flash-Lite charges $0.40 per million output tokens, against $0.50 for GPT-6 Luna Pro. Output dominates the bill when answers are long.
Latest release
Choose GPT-6 Luna Pro
GPT-6 Luna Pro is the newer release (Sep 22, 2026, against July 2025 for Gemini 2.5 Flash-Lite).
Monthly cost at three volumes
| Volume | Gemini 2.5 Flash-Lite | GPT-6 Luna Pro | Difference |
|---|---|---|---|
| Prototype: 1M input, 250K output tokens | $0.20 | $0.23 | Gemini 2.5 Flash-Lite, $0.03 less |
| Production: 20M input, 5M output tokens | $4.00 | $4.50 | Gemini 2.5 Flash-Lite, $0.50 less |
| Scale: 500M input, 100M output tokens | $90.00 | $100.00 | Gemini 2.5 Flash-Lite, $10.00 less |
Standard rates, without caching or batch discounts. Volumes are per month.
Specifications side by side
| Gemini 2.5 Flash-Lite | GPT-6 Luna Pro | |
|---|---|---|
| Provider | OpenAI | |
| Category | Language models | Language models |
| Status | Legacy | Generally available |
| Headline price | $0.175 / 1M tokens | $0.20 / 1M tokens |
| Input | $0.10 / 1M tokens | $0.10 / 1M tokens |
| Output | $0.40 / 1M tokens | $0.50 / 1M tokens |
| Cached input | $0.01 / 1M tokens | $0.01 / 1M tokens |
| Context window | 1.05M | 1.05M |
| Max output | 66k | 128k |
| Released | July 2025 | Sep 22, 2026 |
| Knowledge cutoff | January 2025 | No data |
| Licence | Proprietary | Proprietary |
| Capabilities | Vision, Reasoning, Tool calling, Structured output, Prompt caching, Batch API | Vision, Reasoning, Tool calling, Structured output, Prompt caching |
| API model id | gemini-2.5-flash-lite | gpt-6-luna-pro |
Benchmarks side by side
Leader in bold.
| Benchmark | Gemini 2.5 Flash-Lite | GPT-6 Luna Pro |
|---|---|---|
| Terminal-Bench Hard | 2.3% | No data |
| GPQA Diamond | 47.4% | No data |
| Humanity's Last Exam | 3.7% | No data |
| IFBench (instruction following) | 31.5% | No data |
| τ²-Bench (agentic tool use) | 19% | No data |
| MMMU-Pro (visual reasoning) | 54% | No data |
| Long-context reasoning (AA-LCR) | 32% | No data |
Independent evaluations by Artificial Analysis, run the same way for every model, at the reasoning setting shown. Percentages unless marked as an index.
Frequently asked questions
Should I choose Gemini 2.5 Flash-Lite or GPT-6 Luna Pro?
Choose Gemini 2.5 Flash-Lite for high-volume, cost-sensitive work and writing and code generation. Choose GPT-6 Luna Pro for the latest release.
Which is cheaper, Gemini 2.5 Flash-Lite or GPT-6 Luna Pro?
Gemini 2.5 Flash-Lite is 13% cheaper than GPT-6 Luna Pro at the headline price ($0.175 / 1M tokens vs $0.20 / 1M tokens).
Which has the larger context window, Gemini 2.5 Flash-Lite or GPT-6 Luna Pro?
GPT-6 Luna Pro reads more per request: 1.05M tokens against 1.05M.
What is the difference between Gemini 2.5 Flash-Lite and GPT-6 Luna Pro?
Gemini 2.5 Flash-Lite is made by Google and GPT-6 Luna Pro by OpenAI. Gemini 2.5 Flash-Lite is 13% cheaper than GPT-6 Luna Pro at the headline price ($0.175 / 1M tokens vs $0.20 / 1M tokens). GPT-6 Luna Pro reads more per request: 1.05M tokens against 1.05M. GPT-6 Luna Pro is the newer model (Sep 22, 2026, against July 2025). Only Gemini 2.5 Flash-Lite offers batch api.
How much do Gemini 2.5 Flash-Lite and GPT-6 Luna Pro cost per month?
At 20 million input and 5 million output tokens a month, Gemini 2.5 Flash-Lite costs $4.00 and GPT-6 Luna Pro costs $4.50, at standard rates.
Which is newer, Gemini 2.5 Flash-Lite or GPT-6 Luna Pro?
GPT-6 Luna Pro was released on Sep 22, 2026 and Gemini 2.5 Flash-Lite on July 2025.