Claude

Anthropic: Claude Sonnet 4.5

Chat
anthropic/claude-sonnet-4.5
CompareGet Started

Claude Sonnet 4.5 is Anthropic's balanced model, released on 2025-09-29, with state-of-the-art performance on SWE-bench Verified. It is well suited to coding, analysis, and general-purpose tasks with an excellent cost-performance ratio, and supports reasoning, vision, tool use, PDF input, and prompt caching. Context window: 1M tokens, output: 64K. Priced at $3/M input and $15/M output tokens. Documents and screenshots can be supplied directly, and cached input reads are billed at $0.3/M tokens. Available via OpenAI and Anthropic protocols.

Context Window
1M
Max Output Tokens
64K
Released
2025-09-29
Capabilities
VisionFunction CallingReasoningPrompt CachingPDF Input
Available Providers
BedrockBedrock
Supported Protocols
OpenAIopenaiAnthropicanthropic

Providers

BedrockBedrock
Input Tokens
$3/M
Output Tokens
$15/M
Cache Read
$0.3/M
Cache Write (5 min)
$3.75/M
Cache Write (1 hour)
$6/M
Web Search
$0.015/R
Protocols
OpenAIopenai/v1/chat/completions/v1/responses
Anthropicanthropic

Code Examples

import anthropic
client = anthropic.Anthropic(
base_url="https://api.ofox.run/anthropic",
api_key="YOUR_OFOX_API_KEY",
)
message = client.messages.create(
model="anthropic/claude-sonnet-4.5",
max_tokens=1024,
messages=[
{"role": "user", "content": "Hello!"}
],
)
print(message.content[0].text)

Uptime & Status

Benchmarks

LMArenaEvaluated as claude-sonnet-4-5-20250929

Anthropic: Claude Sonnet 4.5 scores 1455 in the Overall category of the LMArena text leaderboard (style control), ranking #47 of 374 models based on 80,800 human preference votes (updated 2026-07-12).

Benchmark scores for claude-sonnet-4-5-20250929 on LMArena
CategoryArena Score95% CIRankVotes
Overall14521458#47 of 37480,800
Hard Prompts14801487#37 of 37446,503
Coding15081518#28 of 36919,133
Math14191437#77 of 3624,906
Creative Writing14481460#21 of 37212,028
Instruction Following14591468#24 of 37423,280
Chinese14701491#64 of 3443,867

Source: LMArena · CC BY 4.0 · Updated 2026-07-12 · Methodology · Ranks compare models within each category of the LMArena text leaderboard (style control). Scores come from third-party human preference evaluations, not from OFOX.

Frequently Asked Questions

Anthropic: Claude Sonnet 4.5 on Ofox.ai costs $3/M per million input tokens and $15/M per million output tokens. Pay-as-you-go, no monthly fees.