Claude 4.5 Sonnet

Name: Claude 4.5 Sonnet
Author: Anthropic

AnthropicProprietaryPending Human Review

Claude 4.5 Sonnet is a high-intelligence frontier model designed for complex agentic workflows, coding, and computer use. It balances capability with speed and cost, positioning it as the workhorse of the Claude 4.5 family. It features 'extended thinking' capabilities (beta) and is optimized for long-horizon tasks, capable of maintaining focus for extended periods (up to 30+ hours in internal tests). It introduces significant improvements in tool use, particularly in interacting with software interfaces and executing complex multi-step plans.

2025-09-29

Unreleased

Decoder-only Transformer

Proprietary

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Specifications

Parameters: Unreleased
Architecture: Decoder-only Transformer
License: Proprietary
Context Window: 200,000 tokens
Max Output: 64,000 tokens
Training Data Cutoff: Jul 2025
Type: multimodal
Modalities: textimage

Benchmark Scores

Advanced Specifications

Model Family: Claude
Finetuned From: Claude 4
API Access: Available
Chat Interface: Available
Multilingual Support: Yes
Variants: claude-sonnet-4-5-20250929

Capabilities & Limitations

Capabilities: codereasoningcomputer useagentic workflowsextended thinkingvisionmultilingual
Known Limitations: knowledge cutoff limits real-time data without toolspotential for hallucinations in ambiguous contexts
Notable Use Cases: complex coding agentssoftware development lifecycle automationlong-horizon task executioncomputer use automation
Function Calling Support: Yes
Tool Use Support: Yes

Resources

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