Claude Opus 4.5 vs Claude Sonnet 4.5
Claude Opus 4.5 and Claude Sonnet 4.5 are closely matched at 38.2 and 32.1 on the LLM Stats Score. Claude Sonnet 4.5 is 1.7x cheaper per token.
Anthropic · Anthropic · Updated for 2026
Which is better?
Claude Opus 4.5 and Claude Sonnet 4.5 are closely matched on the overall LLM Stats Score at 38.2 and 32.1.
In the 3 individual benchmarks reported for both models, Claude Opus 4.5 wins 3; this is a narrower head-to-head signal than the composite indexes.
On price, Claude Sonnet 4.5 is roughly 1.7x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose Claude Opus 4.5
- your work emphasizes reasoning — it leads those capability indexes
- you value its reported benchmark strengths — it wins 3 of 3 exact shared results
- you want the most recent training data — it shipped Nov 2025
Choose Claude Sonnet 4.5
- cost matters — it's about 1.7x cheaper per token
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
11 reported for Claude Opus 4.5 · 9 for Claude Sonnet 4.5
Claude Opus 4.5 outperforms in 3 benchmarks (GPQA, MMMLU, OSWorld), while Claude Sonnet 4.5 is better at 0 benchmarks.
Claude Opus 4.5 significantly outperforms across most benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Claude Opus 4.5 ($5.00/1M tokens) is 1.7x more expensive than Claude Sonnet 4.5 ($3.00/1M tokens).
For output processing, Claude Opus 4.5 ($25.00/1M tokens) is 1.7x more expensive than Claude Sonnet 4.5 ($15.00/1M tokens).
In conclusion, Claude Opus 4.5 is more expensive than Claude Sonnet 4.5.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Both models have the same input context window of 200,000 tokens. Both models can generate responses up to 64,000 tokens.
Input capabilities
Documented input modalities across available providers
Both Claude Opus 4.5 and Claude Sonnet 4.5 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Claude Opus 4.5
Claude Sonnet 4.5
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 Opus 4.5 was released on 2025-11-24, while Claude Sonnet 4.5 was released on 2025-09-29.
Claude Opus 4.5 is 2 months newer than Claude Sonnet 4.5.
Nov 24, 2025
10 months ago
1mo newerSep 29, 2025
12 months ago
Knowledge Cutoff
When training data ends
Claude Opus 4.5 has a knowledge cutoff of 2025-03-31, while Claude Sonnet 4.5 has a cutoff of 2025-01-31.
Claude Opus 4.5 has more recent training data (up to 2025-03-31), making it potentially better informed about events through that date compared to Claude Sonnet 4.5 (2025-01-31).
Mar 2025
2 mo newerJan 2025
Provider Availability
Claude Opus 4.5 is available from Anthropic. Claude Sonnet 4.5 is available from Anthropic.
Claude Opus 4.5
Claude Sonnet 4.5
Outputs Comparison
Judge for yourself.
Run your own prompts against Claude Opus 4.5 and Claude Sonnet 4.5 side-by-side, then vote on the output you prefer.
FAQ
Common questions about Claude Opus 4.5 vs Claude Sonnet 4.5.