Google Gemini vs OpenAI GPT: Complete Comparison 2026
Compare Google Gemini 3.8 Flash with OpenAI GPT-6 Astra, Sol, and Luna using current October pricing and context limits.
Last updated: October 2026
Pricing Comparison
| Model | Provider | Input $/1M | Output $/1M | Context | Max Output |
|---|---|---|---|---|---|
| Gemini 3.8 Flash | $0.75 | $3.75 | 1.05M | 65K | |
| GPT-6 Astra | OpenAI | $10 | $50 | 1.05M | 128K |
| GPT-6 Luna | OpenAI | $0.1 | $0.5 | 1.05M | 128K |
| GPT-6.1 Sol | OpenAI | $2 | $10 | 1.05M | 128K |
Detailed Comparison
Gemini 3.8 Flash
$0.75 / $3.75
per 1M tokens
Strengths
- + Current GA Flash workhorse
- + 2026 introductory rate
- + Native text, image, video, audio, and PDF input
Best For
High-volume multimodal and agent workloads
Context Window
1.05M
Max Output
65K
GPT-6 Astra
OpenAI
$10 / $50
per 1M tokens
Strengths
- + Broader ecosystem support
- + More mature API and tooling
- + Strong multi-modal capabilities
Best For
Enterprise applications, broad integration needs
Context Window
1.05M
Max Output
128K
GPT-6 Luna
OpenAI
$0.1 / $0.5
per 1M tokens
Strengths
- + Lowest-cost current GPT-6 route
- + Very low $0.10/$0.50 rate
- + OpenAI ecosystem compatibility
Best For
High-volume OpenAI-compatible routing
Context Window
1.05M
Max Output
128K
GPT-6.1 Sol
OpenAI
$2 / $10
per 1M tokens
Strengths
- + Large 1.05M context window
- + Good balance of price and quality
- + Reliable for production
Best For
Production workloads needing large context
Context Window
1.05M
Max Output
128K
Verdict
Gemini 3.8 Flash is $0.75/$3.75 through 2026 with broad multimodal input. GPT-6 Luna is cheaper at $0.10/$0.50, GPT-6.1 Sol is the $2/$10 escalation tier, and Astra is the premium $10/$50 route. Gemini pricing doubles on January 1, 2027.
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FAQ
Which is cheaper, Gemini 3.8 Flash or GPT-6 Astra?
Gemini 3.8 Flash costs $0.75/$3.75 per million tokens (input/output), while GPT-6 Astra costs $10/$50. Gemini 3.8 Flash is cheaper for input.
Which has a larger context window?
Gemini 3.8 Flash supports 1.05M context, while GPT-6 Astra supports 1.05M. Larger context windows allow processing more text in a single request.
Which should I choose for my project?
Gemini 3.8 Flash is $0.75/$3.75 through 2026 with broad multimodal input. GPT-6 Luna is cheaper at $0.10/$0.50, GPT-6.1 Sol is the $2/$10 escalation tier, and Astra is the premium $10/$50 route. Gemini pricing doubles on January 1, 2027.