Claude Opus 5.5 vs Gemini 3.1 Pro Preview Custom Tools

Price, context window & benchmark comparison

Claude Opus 5.5

Anthropic

$4.00 / $20.00

Input / Output · per 1M tokens

Gemini 3.1 Pro Preview Custom Tools

Google

$2.00 / $12.00

Input / Output · per 1M tokens

Compare different models

Verdict: Gemini 3.1 Pro Preview Custom Tools is 44% cheaper than Claude Opus 5.5 on a typical 3:1 input/output mix. Gemini 3.1 Pro Preview Custom Tools has the larger context window (1M vs 1M).

	Claude Opus 5.5	Gemini 3.1 Pro Preview Custom Tools
Input price / 1M	$4.00	$2.00
Output price / 1M	$20.00	$12.00
Blended price (3:1)	$8.00	$4.50
Cached input / 1M	$0.20	$0.20
Context window	1M	1M
Max output	128K	66K
Intelligence index	57.6	—
Coding index	—	—
Providers	11	—
Best provider uptime (30m)	100.0%	—
Vision input	Yes	Yes
Reasoning	Yes	Yes
Tool calling	Yes	Yes
Released	2026-09-22	2026-02-25
Retirement	—	—

Cost calculator

Input tokens / requestOutput tokens / requestRequests / day

FAQ

Which is cheaper, Claude Opus 5.5 or Gemini 3.1 Pro Preview Custom Tools?

Gemini 3.1 Pro Preview Custom Tools is 44% cheaper than Claude Opus 5.5 on a typical 3:1 input/output mix.

Claude Opus 5.5 vs Gemini 3.1 Pro Preview Custom Tools: which has a bigger context window?

Claude Opus 5.5: 1,000,000 tokens. Gemini 3.1 Pro Preview Custom Tools: 1,048,576 tokens.

How much would 1 million requests cost?

At 2,000 input + 500 output tokens per request: Claude Opus 5.5 ≈ $18,000, Gemini 3.1 Pro Preview Custom Tools ≈ $10,000.

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