Model Comparison
Claude Sonnet 4.5 vs Gemini 2.5 ProWhich is better in 2026?
Claude Sonnet 4.5 significantly outperforms across most benchmarks. Gemini 2.5 Pro is 1.7x cheaper per token.
Verdict: Claude Sonnet 4.5 vs Gemini 2.5 Pro — which is better?
Claude Sonnet 4.5 (by Anthropic) and Gemini 2.5 Pro (by Google) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.
Claude Sonnet 4.5 outperforms in 2 benchmarks (AIME 2025, GPQA), while Gemini 2.5 Pro is better at 0 benchmarks. Claude Sonnet 4.5 significantly outperforms across most benchmarks.
On price, Gemini 2.5 Pro is roughly 1.7x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Gemini 2.5 Pro also accepts a larger context window (1,048,576 input tokens), making it the stronger choice for long documents and large codebases.
Choose Claude Sonnet 4.5 if…
- you want the strongest raw capability — it leads on 2 of 2 shared benchmarks
- you want the most recent training data — it shipped Sep 2025
Choose Gemini 2.5 Pro if…
- cost matters — it's about 1.7x cheaper per token
- you process long inputs — it offers a 1,048,576 token context window
Performance Benchmarks
Comparative analysis across standard metrics
Claude Sonnet 4.5 outperforms in 2 benchmarks (AIME 2025, GPQA), while Gemini 2.5 Pro is better at 0 benchmarks.
Claude Sonnet 4.5 significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, Claude Sonnet 4.5 ($3.00/1M tokens) is 2.4x more expensive than Gemini 2.5 Pro ($1.25/1M tokens).
For output processing, Claude Sonnet 4.5 ($15.00/1M tokens) is 1.5x more expensive than Gemini 2.5 Pro ($10.00/1M tokens).
In conclusion, Claude Sonnet 4.5 is more expensive than Gemini 2.5 Pro.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Gemini 2.5 Pro accepts 1,048,576 input tokens compared to Claude Sonnet 4.5's 200,000 tokens. Gemini 2.5 Pro can generate longer responses up to 65,536 tokens, while Claude Sonnet 4.5 is limited to 64,000 tokens.
Input Capabilities
Supported data types and modalities
Both Claude Sonnet 4.5 and Gemini 2.5 Pro support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Claude Sonnet 4.5
Gemini 2.5 Pro
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
Claude Sonnet 4.5 was released on 2025-09-29, while Gemini 2.5 Pro was released on 2025-05-20.
Claude Sonnet 4.5 is 4 months newer than Gemini 2.5 Pro.
Sep 29, 2025
10 months ago
4mo newerMay 20, 2025
1.2 years ago
Knowledge Cutoff
When training data ends
Both models have the same knowledge cutoff date of 2025-01-31.
They should have similar awareness of historical events and information up to this date.
Jan 2025
Jan 2025
Provider Availability
Claude Sonnet 4.5 is available from Anthropic. Gemini 2.5 Pro is available from Google.
Claude Sonnet 4.5
Gemini 2.5 Pro
Outputs Comparison
Key Takeaways
Claude Sonnet 4.5
View detailsAnthropic
Claude Sonnet 4.5Gemini 2.5 ProDetailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against Claude Sonnet 4.5 and Gemini 2.5 Pro side-by-side, then vote on the output you prefer.
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FAQ
Common questions about Claude Sonnet 4.5 vs Gemini 2.5 Pro.