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GPT-5 vs Gemini 3.1 Pro: price comparison

Real 2026 API prices side by side, with the total cost of a typical 10M-input / 3M-output monthly workload.

Price & cost at a glance

	GPT-5	Gemini 3.1 Pro
Input / 1M tokens	$1.25	$2
Output / 1M tokens	$10	$12
Context window	400K	2000K
Cost — 10M in + 3M out	$42.5	$56

Green = cheaper / larger. Prices per 1M tokens, USD. Snapshot 2026 — verify with the provider.

Which is cheaper?

GPT-5 is the cheaper option on a 10M-in / 3M-out workload — about $42.5/mo versus $56 for Gemini 3.1 Pro (~1.3× difference). Because output tokens are billed higher, the model with the lower output price usually wins as your responses get longer.

Run your own token mix in the cost calculator, or see each model in depth: GPT-5 · Gemini 3.1 Pro.

Frequently asked

Is GPT-5 or Gemini 3.1 Pro cheaper?

At a typical 10M input + 3M output tokens per month, GPT-5 costs about $42.5 versus $56 for Gemini 3.1 Pro — GPT-5 is roughly 1.3x cheaper on this workload. Your ratio of input to output tokens changes the gap.

What's the price difference between GPT-5 and Gemini 3.1 Pro?

GPT-5 is $1.25/$10 per 1M input/output tokens; Gemini 3.1 Pro is $2/$12. Output tokens usually dominate a bill, so compare the output price first.

Which has the bigger context window, GPT-5 or Gemini 3.1 Pro?

GPT-5 supports about 400K tokens and Gemini 3.1 Pro about 2000K. A bigger window costs more per call because every token in context is billed.

Related comparisons

GPT-5 vs Claude Opus 4.8 Claude Opus 4.8 vs Gemini 3.1 Pro GPT-5 vs Grok 4 GPT-5.5 vs GPT-5 GPT-5 vs DeepSeek R1 All 387 models →

Educational estimates — not affiliated with any provider.