Head-to-head · Google vs OpenAI
Gemini 3.8 Flash vs GPT-6 Luna
Quick answer: Gemini 3.8 Flash stands out for strong quality for a fast, low-cost model. GPT-6 Luna stands out for extremely cheap for bulk processing. Reviewed September 2026.
Overview
Gemini 3.8 Flash: Gemini 3.8 Flash, released on 2 September 2026, is Google's newest Flash model, aimed at long-horizon engineering and agent tasks. It is priced at $0.75 and $3.75 per million tokens, a rate Google lists through 31 December 2026, after which it rises to $1.50 and $7.50.
GPT-6 Luna: GPT-6 Luna, launched on 22 September 2026, is the small, low-cost member of the GPT-6 family at $0.10 and $0.50 per million tokens. It targets high-volume tasks where cost and speed matter most.
At a glance
| Dimension | Gemini 3.8 Flash | GPT-6 Luna |
|---|---|---|
| Vendor | OpenAI | |
| Starting price | API: $0.75 in / $3.75 out per M tokens | API: $0.10 in / $0.50 out per M tokens |
| Pricing model | Paid | Paid |
| Free tier | No | No |
| Category | Generative AI | Generative AI |
Strengths and limits
Gemini 3.8 Flash
- Strong quality for a fast, low-cost model
- Well suited to agentic and coding workflows
- Backed by Google's multimodal stack
Watch out for
- Listed price applies through 31 December 2026
- Below Pro-tier models on the hardest reasoning
- Very new, so limited independent evaluations
GPT-6 Luna
- Extremely cheap for bulk processing
- Fast responses
- Good fit for classification and extraction
Watch out for
- Not suited to the hardest reasoning tasks
- Newest release with limited track record
- Quality varies by task, so test on your own data
Key features
Gemini 3.8 Flash
- Latest Flash-tier Gemini model
- Built for agents and long-horizon engineering tasks
- Low per-token price
- Available through the Gemini API
GPT-6 Luna
- Very low per-token pricing
- Built for high-volume and latency-sensitive work
- Shares GPT-6 family technology
- Available through the OpenAI API
Pricing compared
Gemini 3.8 Flash is priced by usage rather than by seat: API: $0.75 in / $3.75 out per M tokens. That means cost scales with how much text you send and receive, so estimate your monthly volume before committing.
GPT-6 Luna is priced by usage rather than by seat: API: $0.10 in / $0.50 out per M tokens. That means cost scales with how much text you send and receive, so estimate your monthly volume before committing.
Frequently asked questions
Which is better, Gemini 3.8 Flash or GPT-6 Luna?
It depends on the work. Gemini 3.8 Flash stands out for strong quality for a fast, low-cost model. GPT-6 Luna stands out for extremely cheap for bulk processing.
How do Gemini 3.8 Flash and GPT-6 Luna compare on price?
Gemini 3.8 Flash is priced by usage rather than by seat: API: $0.75 in / $3.75 out per M tokens. That means cost scales with how much text you send and receive, so estimate your monthly volume before committing. GPT-6 Luna is priced by usage rather than by seat: API: $0.10 in / $0.50 out per M tokens. That means cost scales with how much text you send and receive, so estimate your monthly volume before committing.
Is there a free option between Gemini 3.8 Flash and GPT-6 Luna?
Neither lists a permanent free tier. Look for trials or usage-based pricing to test on real work first.