Head-to-head · Anthropic vs Google

Claude Opus 5.5 vs Gemini 3.1 Pro

CO
Claude Opus 5.5
Anthropic · API: $4 in / $20 out per M tokens
vs
G3
Gemini 3.1 Pro
Google · API: $2 in / $12 out per M tokens

Quick answer: Claude Opus 5.5 stands out for matches Claude Fable 5.1 on most work at a much lower price. Gemini 3.1 Pro stands out for strong multimodal coverage. Reviewed September 2026.

Overview

Claude Opus 5.5: Claude Opus 5.5, released on 22 September 2026, is Anthropic's newest Opus model. Anthropic reports it performs at the level of Claude Fable 5.1 on most work while costing about 40% less to run than Opus 5, with a focus on agentic coding, computer use and knowledge work.

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 Opus 5.5Gemini 3.1 Pro
VendorAnthropicGoogle
Starting priceAPI: $4 in / $20 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 Opus 5.5

  • Matches Claude Fable 5.1 on most work at a much lower price
  • Faster output than Opus 5
  • Strong on coding and knowledge work such as financial analysis

Watch out for

  • Newest release, so fewer independent long-term evaluations
  • Output still costs $20 per million tokens
  • Sonnet or Haiku are cheaper for routine tasks

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 Opus 5.5

  • 1M-token context window at standard pricing
  • Agentic coding, code review and bug detection
  • Computer use and complex multi-step tasks
  • Clearer, more direct communication style
  • Available in Claude apps, the API, Claude Code, AWS, Google Cloud and Microsoft Azure

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 Opus 5.5 is priced by usage rather than by seat: API: $4 in / $20 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 Opus 5.5 or Gemini 3.1 Pro?

It depends on the work. Claude Opus 5.5 stands out for matches Claude Fable 5.1 on most work at a much lower price. Gemini 3.1 Pro stands out for strong multimodal coverage.

How do Claude Opus 5.5 and Gemini 3.1 Pro compare on price?

Claude Opus 5.5 is priced by usage rather than by seat: API: $4 in / $20 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 Opus 5.5 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