Head-to-head · Anthropic vs Google

Claude Sonnet 5 vs Gemini 3.1 Pro

CS
Claude Sonnet 5
Anthropic · API: $2 in / $10 out per M tokens
vs
G3
Gemini 3.1 Pro
Google · API: $2 in / $12 out per M tokens

Quick answer: Claude Sonnet 5 stands out for lower price than Sonnet 4.6 with newer capabilities. Gemini 3.1 Pro stands out for strong multimodal coverage. Reviewed September 2026.

Overview

Claude Sonnet 5: Claude Sonnet 5 is the mid-tier model in the Claude 5 family and the default choice for most professional work. Anthropic made its launch pricing of $2 and $10 per million tokens permanent, which makes it one of the best price-to-quality options in the lineup.

Gemini 3.1 Pro: Gemini 3.1 Pro, released by Google in February 2026, is a multimodal model with strong agentic capabilities. It is listed at $2 and $12 per million tokens for prompts up to 200,000 tokens ($4 and $18 above that) and is offered in preview on the Gemini API.

At a glance

DimensionClaude Sonnet 5Gemini 3.1 Pro
VendorAnthropicGoogle
Starting priceAPI: $2 in / $10 out per M tokensAPI: $2 in / $12 out per M tokens
Pricing model Paid Paid
Free tier No No
CategoryGenerative AIGenerative AI

Strengths and limits

Claude Sonnet 5

  • Lower price than Sonnet 4.6 with newer capabilities
  • Fast enough for interactive use
  • Handles most tasks that do not need Opus-level depth

Watch out for

  • Below Opus on the hardest reasoning tasks
  • Sonnet 5.5 is announced as coming soon
  • Image generation is not built in

Gemini 3.1 Pro

  • Strong multimodal coverage
  • Deep Google ecosystem integration
  • Competitive price for a Pro-tier model

Watch out for

  • Listed as a preview model on the pricing page
  • Google has said Gemini 4 is coming
  • Output style can vary between interfaces

Key features

Claude Sonnet 5

  • Balanced speed and quality for everyday work
  • Strong on drafting, analysis and code review
  • Computer use and tool use
  • Batch pricing at half the standard rate
  • Available through Claude apps, the API and major clouds

Gemini 3.1 Pro

  • Multimodal understanding across text, images, audio and video
  • Agentic and tool-use capabilities
  • Tiered pricing for prompts over 200,000 tokens
  • Available through the Gemini API and Google Cloud

Pricing compared

Claude Sonnet 5 is priced by usage rather than by seat: API: $2 in / $10 out per M tokens. That means cost scales with how much text you send and receive, so estimate your monthly volume before committing.

Gemini 3.1 Pro is priced by usage rather than by seat: API: $2 in / $12 out per M tokens. That means cost scales with how much text you send and receive, so estimate your monthly volume before committing.

Frequently asked questions

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

It depends on the work. Claude Sonnet 5 stands out for lower price than Sonnet 4.6 with newer capabilities. Gemini 3.1 Pro stands out for strong multimodal coverage.

How do Claude Sonnet 5 and Gemini 3.1 Pro compare on price?

Claude Sonnet 5 is priced by usage rather than by seat: API: $2 in / $10 out per M tokens. That means cost scales with how much text you send and receive, so estimate your monthly volume before committing. Gemini 3.1 Pro is priced by usage rather than by seat: API: $2 in / $12 out per M tokens. That means cost scales with how much text you send and receive, so estimate your monthly volume before committing.

Is there a free option between Claude Sonnet 5 and Gemini 3.1 Pro?

Neither lists a permanent free tier. Look for trials or usage-based pricing to test on real work first.

Read the full reviews