Which is cheaper, Claude Sonnet 5 or Gemini 3.1 Pro?

Claude Sonnet 5. On a task of 1,500 input and 500 output tokens across 3 calls, Claude Sonnet 5 costs $0.02400 per task against $0.02700 for Gemini 3.1 Pro, which makes it 1.12x cheaper (a 11% saving).

How much do Claude Sonnet 5 and Gemini 3.1 Pro charge per million tokens?

Claude Sonnet 5: $2 per million input tokens and $10 per million output tokens. Gemini 3.1 Pro: $2 input and $12 output. These are published list rates as of August 2026, excluding cached, batch and long-context tiers.

What does a million tasks cost on Claude Sonnet 5 vs Gemini 3.1 Pro?

At the same fixed profile, one million tasks cost $24,000 on Claude Sonnet 5 and $27,000 on Gemini 3.1 Pro. The gap comes entirely from list-price differences, not from any difference in the work done.

Model price comparisons · August 2026

Claude Sonnet 5 vs Gemini 3.1 Pro: API pricing compared

Same task, same tokens, two invoices. Every figure on this page is computed from our open pricing dataset, not copied from a blog post.

Claude Sonnet 5 is 1.12x cheaper than Gemini 3.1 Pro on a realistic task profile of 1,500 input and 500 output tokens per call, 3 calls per task: $0.02400 against $0.02700 per task, a 11% saving on identical work. Run a million tasks a month and that is the difference between $24,000 and $27,000.

Model	Input $/1M tok	Output $/1M tok	Output multiple	$/task	$/1M tasks
Claude Sonnet 5Anthropic · mid	$2	$10	5x	$0.02400	$24,000
Gemini 3.1 ProGoogle · frontier	$2	$12	6x	$0.02700	$27,000

Monthly bill at three volumes

Tasks / month	Claude Sonnet 5	Gemini 3.1 Pro	Gap
10,000	$240	$270	$30
100,000	$2,400	$2,700	$300
1,000,000	$24,000	$27,000	$3,000

Where the money goes on each

Claude Sonnet 5 prices output at 5x its input rate, so on this profile output is 63% of its task cost. Gemini 3.1 Pro prices output at 6x input, putting output at 67% of cost. The model with the higher output multiple rewards capping response length more; the one with the higher input share rewards prompt caching and context trimming more. Cost tells you nothing about quality: run both on twenty of your real cases before deciding, and treat the cheaper model as the default until it demonstrably fails.

Break-even against a dedicated GPU

Against a $2/hour dedicated instance ($1,460/month fixed), self-hosting overtakes Claude Sonnet 5 at 60,833 tasks per month and overtakes Gemini 3.1 Pro at 54,074 tasks per month. The full method is in the self-hosting break-even guide.

Pricing the self-hosted side? Compare on-demand GPU rates:

Compare GPU cloud pricing →

Plug your own token counts into the $/task calculator, or read the full ten-model pricing comparison.

Compare against other models

Frequently asked

Which is cheaper, Claude Sonnet 5 or Gemini 3.1 Pro?: Claude Sonnet 5. On a task of 1,500 input and 500 output tokens across 3 calls, Claude Sonnet 5 costs $0.02400 per task against $0.02700 for Gemini 3.1 Pro, which makes it 1.12x cheaper (a 11% saving).
How much do Claude Sonnet 5 and Gemini 3.1 Pro charge per million tokens?: Claude Sonnet 5: $2 per million input tokens and $10 per million output tokens. Gemini 3.1 Pro: $2 input and $12 output. These are published list rates as of August 2026, excluding cached, batch and long-context tiers.
What does a million tasks cost on Claude Sonnet 5 vs Gemini 3.1 Pro?: At the same fixed profile, one million tasks cost $24,000 on Claude Sonnet 5 and $27,000 on Gemini 3.1 Pro. The gap comes entirely from list-price differences, not from any difference in the work done.