Which is cheaper, Claude Opus 4.5 or Gemini 3 Flash?

Gemini 3 Flash is cheaper for the default 10,000 input and 10,000 output token scenario.

What is the context window for Claude Opus 4.5?

Claude Opus 4.5 supports a context window of 200K.

What is the context window for Gemini 3 Flash?

Gemini 3 Flash supports a context window of 1M.

Model Comparison

v2.0

Price Data Last Verified: March 21, 2026

Claude Opus 4.5 vs Gemini 3 Flash: AI API Cost Comparison (2026)

This page compares per-token pricing and context limits for Claude Opus 4.5 and Gemini 3 Flashusing a standard scenario of 10,000 input tokens and 10,000 output tokens.

Model A

Claude Opus 4.5

Anthropic

Input / 1M: $5.00
Output / 1M: $25.00
Context Window: 200K

Model B

Gemini 3 Flash

Google

Input / 1M: $0.50
Output / 1M: $3.00
Context Window: 1M

Cost Breakdown Table

Model	Input Cost	Output Cost	Total Cost
Claude Opus 4.5	$0.05	$0.25	$0.30
Gemini 3 Flash	$0.005	$0.03	$0.035

Verdict

High Volume

Best pick: Gemini 3 Flash for a 2,000,000 in /2,000,000 out workload.

Low Budget

Best pick: Gemini 3 Flash for a 10,000 in /10,000 out request profile.

About the Methodology

Cost estimates are generated from published input and output token rates for each provider. We apply identical token scenarios to both models in this comparison, so the result reflects price differences only. Pricing values are reviewed weekly against official API documentation and updated when changes are verified.

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