Claude Opus 4.5 (Reasoning) vs Gemini 2.5 Flash Preview (Sep '25) (Reasoning): The Ultimate Performance & Pricing Comparison

Deep dive into reasoning, benchmarks, and latency insights.

The Final Verdict in the Claude Opus 4.5 (Reasoning) vs Gemini 2.5 Flash Preview (Sep '25) (Reasoning) Showdown

After a comprehensive analysis, Claude Opus 4.5 (Reasoning) emerges as the superior choice for users prioritizing raw intelligence and reasoning. However, Gemini 2.5 Flash Preview (Sep '25) (Reasoning) remains a highly competitive option, especially for scenarios demanding faster response times and cost-efficiency. This detailed Claude Opus 4.5 (Reasoning) vs Gemini 2.5 Flash Preview (Sep '25) (Reasoning) comparison will break down every critical metric to help you make the best decision.

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Model Snapshot

Key decision metrics at a glance.

Claude Opus 4.5 (Reasoning)

Anthropic

Reasoning: 9
Coding: 5
Multimodal: 4
Long Context: 6
Blended Price / 1M tokens: $0.010
P95 Latency: 1000ms
Tokens per second: 80.264tokens/sec

Gemini 2.5 Flash Preview (Sep '25) (Reasoning)

Google

Reasoning: 8
Coding: 2
Multimodal: 3
Long Context: 4
Blended Price / 1M tokens: $0.001
P95 Latency: 1000ms
Tokens per second: 295.309tokens/sec

Overall Capabilities

The capability radar provides a holistic view of the Claude Opus 4.5 (Reasoning) vs Gemini 2.5 Flash Preview (Sep '25) (Reasoning) matchup. This chart illustrates each model's strengths and weaknesses at a glance, forming a cornerstone of our Claude Opus 4.5 (Reasoning) vs Gemini 2.5 Flash Preview (Sep '25) (Reasoning) analysis.

This radar chart visually maps the core capabilities (reasoning, coding, math proxy, multimodal, long context) of `Claude Opus 4.5 (Reasoning)` vs `Gemini 2.5 Flash Preview (Sep '25) (Reasoning)`.

Benchmark Breakdown

For a granular look, this chart directly compares scores across standardized benchmarks. In the critical MMLU Pro test, a key part of the Claude Opus 4.5 (Reasoning) vs Gemini 2.5 Flash Preview (Sep '25) (Reasoning) debate, Claude Opus 4.5 (Reasoning) scores 90 against Gemini 2.5 Flash Preview (Sep '25) (Reasoning)'s 80. This data-driven approach is essential for any serious Claude Opus 4.5 (Reasoning) vs Gemini 2.5 Flash Preview (Sep '25) (Reasoning) comparison.

This grouped bar chart provides a side-by-side comparison for each benchmark metric.

Speed & Latency

Speed is a crucial factor in the Claude Opus 4.5 (Reasoning) vs Gemini 2.5 Flash Preview (Sep '25) (Reasoning) decision for interactive applications. The metrics below highlight the trade-offs you should weigh before shipping to production.

Time to First Token

Claude Opus 4.5 (Reasoning)300ms

Gemini 2.5 Flash Preview (Sep '25) (Reasoning)300ms

Tokens per Second

Claude Opus 4.5 (Reasoning)80.264

Gemini 2.5 Flash Preview (Sep '25) (Reasoning)295.309

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The Economics of Claude Opus 4.5 (Reasoning) vs Gemini 2.5 Flash Preview (Sep '25) (Reasoning)

Power is only one part of the equation. This Claude Opus 4.5 (Reasoning) vs Gemini 2.5 Flash Preview (Sep '25) (Reasoning) pricing analysis gives you a true sense of value.

Pricing Breakdown

Compare input and output pricing at a glance.

Real-World Cost Scenario

To process 1M input tokens and generate 250k output tokens, Claude Opus 4.5 (Reasoning) would cost $0.011, whereas Gemini 2.5 Flash Preview (Sep '25) (Reasoning) would cost $0.001. This practical calculation is vital for any developer considering the Claude Opus 4.5 (Reasoning) vs Gemini 2.5 Flash Preview (Sep '25) (Reasoning) choice.

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Which Model Wins the Claude Opus 4.5 (Reasoning) vs Gemini 2.5 Flash Preview (Sep '25) (Reasoning) Battle for You?

Choose Claude Opus 4.5 (Reasoning) if...

Your top priority is raw performance and capability.

You are working in a technical or scientific field requiring the highest accuracy.

Cost is a secondary concern to power in your Claude Opus 4.5 (Reasoning) vs Gemini 2.5 Flash Preview (Sep '25) (Reasoning) decision.

Choose Gemini 2.5 Flash Preview (Sep '25) (Reasoning) if...

You need a highly responsive model for user-facing applications.

Your budget is a primary consideration in the Claude Opus 4.5 (Reasoning) vs Gemini 2.5 Flash Preview (Sep '25) (Reasoning) choice.

You are developing at scale where operational costs are critical.

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Your Questions about the Claude Opus 4.5 (Reasoning) vs Gemini 2.5 Flash Preview (Sep '25) (Reasoning) Comparison

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Data source: https://artificialanalysis.ai/