Anthropic: Claude Sonnet 4.5

by Anthropic

Claude Sonnet 4.5 is Anthropic’s most advanced Sonnet model to date, optimized for real-world agents and coding workflows. It delivers state-of-the-art performance on coding benchmarks such as SWE-bench Verified, with improvements across system design, code security, and specification adherence. The...

*Artificial Analysis‡Kilo Code Leaderboard†OpenRouter
Release Date
September 29, 2025
Context Window
1,000,000 tokens
Max Output
64,000 tokens
Input Modalities
textimagefile

Coding Performance

Coding benchmarks and performance metrics for development tasks

Coding Benchmarks

Artificial Analysis Coding Index

49.8%

Overall coding capability score

LiveCodeBench

71.4%

Real-world coding task performance

SciCode

44.7%

Scientific computing & algorithms

TerminalBench Hard

33.3%

CLI & terminal command generation

LCR (Long Context Reasoning)

65.7%

Understanding large codebases

IFBench

57.3%

Instruction following accuracy

Speed & Efficiency

Output Speed

50.4 tokens/sec

Median output tokens per second

Time to First Token

2.1s

Median responsiveness

Performance metrics from Artificial Analysis

Real-World Usage

Real-world usage statistics from the Kilo Code community

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Real-world metrics from the Kilo Code Leaderboard

Pricing

Cost per 1 million tokens

Input Tokens
$3.00
per 1M tokens
Output Tokens
$15.00
per 1M tokens
Blended (3:1 ratio)
$6.00
per 1M tokens

Example Cost

Analyzing a 10,000 line codebase (≈40k input tokens, 10k output tokens) costs approximately $0.2700

Coding Capabilities

Features and parameters relevant to coding tasks

Coding Features

Function Calling
Can call external functions/APIs
Tool Choice
Control over function selection
Structured Outputs
JSON schema validation
Reasoning Tokens
Extended thinking for complex problems

Pricing details from OpenRouter

Technical Details

Architecture and implementation specifications

Model ID
anthropic/claude-sonnet-4.5
Created
September 29, 2025
Tokenizer
Claude
Input Modalities
text, image, file
Context Window
1,000,000 tokens
Max Completion Tokens
64,000 tokens
Input Price
$3.00 per 1M tokens
Output Price
$15.00 per 1M tokens
Cache Read Price
$0.30 per 1M tokens
Cache Write Price
$3.75 per 1M tokens
Content Moderation
Disabled

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