GPT-4o mini vs Gemini 3.8 Flash
Detailed pricing comparison and cost analysis.
Updated September 2026
Cost Simulator
| Feature | GPT-4o mini | Gemini 3.8 Flash |
|---|---|---|
| Provider | OpenAI | |
| Input Price (1M) | $0.15 | $0.75 |
| Output Price (1M) | $0.60 | $3.75 |
| Context Window | 128,000 | 1,000,000 |
Verdict
GPT-4o mini costs $0.15 per 1M input tokens and $0.60 per 1M output tokens. Gemini 3.8 Flash costs $0.75 per 1M input tokens and $3.75 per 1M output tokens. GPT-4o mini is 80% cheaper on input tokens than Gemini 3.8 Flash. For output tokens, GPT-4o mini is the more affordable option at $0.60/1M vs $3.75.
On context window, Gemini 3.8 Flash supports 1,000,000 tokens — meaning it can fit more conversation history, documents, or code in a single request. This matters for RAG pipelines, long document analysis, and agentic workflows where context builds up over many turns.
When to choose GPT-4o mini
- ✓ You need the lowest input token cost ($ 0.15/1M)
- ✓ Your workload is output-heavy — GPT-4o mini generates text cheaper
- ✓ You are already integrated with OpenAI
When to choose Gemini 3.8 Flash
- ✓ You need a larger context window (1,000,000 tokens)
- ✓ You are already integrated with Google
Use the calculator above to simulate your specific workload and find the exact break-even point. For most applications, the cheapest model is the one that minimises your total monthly bill given your input-to-output token ratio.
Frequently Asked Questions
Is GPT-4o mini cheaper than Gemini 3.8 Flash? ▼
GPT-4o mini is cheaper on input tokens at $0.15/1M vs $0.75/1M for Gemini 3.8 Flash — a 80% saving.
What is the context window of GPT-4o mini vs Gemini 3.8 Flash? ▼
GPT-4o mini has a 128,000-token context window. Gemini 3.8 Flash has a 1,000,000-token context window. Gemini 3.8 Flash supports the larger context, suitable for longer documents and agentic workflows.
Which model is better: GPT-4o mini or Gemini 3.8 Flash? ▼
The best choice depends on your use case. For cost efficiency on input tokens, GPT-4o mini is the cheaper option. For maximum context length, Gemini 3.8 Flash supports 1,000,000 tokens. Use the comparison table above to find the right fit for your workload.