Gemini 3.5 Flash vs GPT-4.1 — LLM API Cost Comparison
Compare Gemini 3.5 Flash (Google) vs GPT-4.1 (OpenAI) on cost per million tokens, context window, and monthly spend.
Prices verified 2026-05-20 · Pricing may change — use the calculator for current estimates
- Input
- $1.5/1M tokens
- Output
- $9/1M tokens
- Context
- 1M tokens
- Released
- 2026-05
Latest Gemini; frontier intelligence + superior search & grounding
- Input
- $2/1M tokens
- Output
- $8/1M tokens
- Context
- 1M tokens
- Released
- 2025-04
Recommended production model (replaced GPT-4o); 1M context
Monthly Cost by Usage Tier (70% input / 30% output ratio)
| Usage | Gemini 3.5 Flash | GPT-4.1 | Cheaper by |
|---|---|---|---|
| Light (1M tokens) | $3.75 | $3.80 | Gemini 3.5 Flash (1%) |
| Moderate (10M tokens) | $37.50 | $38.00 | Gemini 3.5 Flash (1%) |
| Heavy (100M tokens) | $375 | $380 | Gemini 3.5 Flash (1%) |
| Very Heavy (1B tokens) | $3,750 | $3,800 | Gemini 3.5 Flash (1%) |
Frequently Asked Questions
Which is cheaper — Gemini 3.5 Flash or GPT-4.1?
For input tokens, Gemini 3.5 Flash is cheaper at $1.5/1M tokens — 1.3× less than $2/1M. For output tokens, GPT-4.1 wins at $8/1M vs $9/1M. At heavy workloads (100M tokens/month), the cost difference can be significant.
What is the context window difference between Gemini 3.5 Flash and GPT-4.1?
Gemini 3.5 Flash supports 1,000,000 tokens per request; GPT-4.1 supports 1,000,000 tokens. Gemini 3.5 Flash wins on context length, making it better for long documents, large codebases, or extended conversations without chunking.
When should I choose Gemini 3.5 Flash over GPT-4.1?
Choose Gemini 3.5 Flash (Google) if you prefer Google's ecosystem, tooling, or reliability track record. Latest Gemini; frontier intelligence + superior search & grounding. Choose GPT-4.1 (OpenAI) if Recommended production model (replaced GPT-4o); 1M context. the price/performance fits your workload better. Use this calculator to find the break-even point for your exact token volume.
How much does 1 billion tokens cost on Gemini 3.5 Flash vs GPT-4.1?
At 700M input + 300M output tokens (1B total): Gemini 3.5 Flash costs $3750; GPT-4.1 costs $3800. The difference is $50/billion tokens at this 70/30 input/output ratio.