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Home/Models/Anthropic/Claude 4 Sonnet
C

Claude 4 Sonnet

Input:$2.4/M
Output:$12/M
Context:200K
Max Output:64K
Fastest, most cost-effective model, 200K context window.
Commercial Use
Playground
Overview
Features
Pricing
API
Versions

Key Features of Claude Sonnet 4

  • Hybrid Reasoning Architecture: Claude Sonnet 4 employs a hybrid reasoning approach, combining rapid response generation with extended, step-by-step thinking. This dual-mode processing allows the model to adapt its reasoning depth based on task complexity.
  • Enhanced Coding and Reasoning: The model demonstrates significant improvements in coding tasks, complex problem-solving, and precise instruction following compared to its predecessors.
  • Improved Memory Retention: Claude Sonnet 4 exhibits better memory retention over long conversations, enabling it to maintain context and coherence in extended interactions.
  • Safety and Coherence: Anthropic emphasizes safety and coherence in Claude Sonnet 4, implementing measures to reduce issues like reward hacking and ensuring reliable performance in various applications.

Technical Specifications

  • Model Type: Large Language Model (LLM), Generative Pre-trained Transformer (GPT), Foundation Model
  • Developer: Anthropic
  • Release Date: May 22, 2025
  • Access: Available to both free and paid users via Anthropic API, Amazon Bedrock, and Google Cloud’s Vertex AI
  • Safety Level: Classified under safety level ASL-3, with steps taken to mitigate potential risks associated with advanced AI capabilities

Evolution from Previous Models

Claude Sonnet 4 builds upon the foundation laid by its predecessor, Claude 3.7 Sonnet, which introduced hybrid reasoning capabilities and demonstrated improved performance in various benchmarks. The evolution to Claude Sonnet 4 includes further enhancements in coding proficiency, reasoning accuracy, and memory retention, positioning it as a more robust and reliable AI model for diverse applications.

Benchmark Performance

Claude Sonnet 4 significantly enhances the capabilities of its predecessor, Sonnet 3.7, excelling in both coding and reasoning tasks with improved precision and controllability. Achieving state-of-the-art performance on SWE-bench (72.7%), Sonnet 4 balances capability and computational efficiency, making it suitable for a broad range of applications from routine coding tasks to complex software development projects. Key enhancements include improved autonomous codebase navigation, reduced error rates in agent-driven workflows, and increased reliability in following intricate instructions.

Technical Indicators

  • Context Window: While specific details for Claude Sonnet 4 are not provided, Claude 3.7 Sonnet featured a context window of 200,000 tokens, suggesting that the newer model maintains or improves upon this capacity.
  • Extended Thinking Mode: Claude Sonnet 4 includes a beta “extended thinking” mode, allowing users to optimize reasoning versus tool use, enhancing the model's adaptability to complex tasks.
  • Thinking Summaries: A new feature that condenses the chatbot’s reasoning process into easily understandable insights, aiding users in comprehending the model's decision-making pathways.

Application Scenarios

Claude Sonnet 4's enhanced capabilities make it suitable for a wide range of applications:

  • Software Development: The model's improved coding proficiency supports tasks such as code generation, debugging, and software refactoring, streamlining development workflows.
  • Customer Support: With better memory retention and reasoning, Claude Sonnet 4 can manage prolonged and intricate customer interactions, providing consistent and coherent support.
  • Data Analysis: The model's ability to process and analyze large datasets enables it to assist in complex data analytics tasks, offering valuable insights and summaries.
  • Educational Tools: Claude Sonnet 4 can serve as an educational assistant, helping students and educators with explanations, problem-solving, and content generation.
  • Content Creation: The model's proficiency in generating coherent and contextually relevant text makes it a valuable tool for content creators in drafting articles, reports, and creative writing.

How to access Claude Sonnet 4 API

Step 1: Sign Up for API Key

Log in to cometapi.com. If you are not our user yet, please register first. Sign into your CometAPI console. Get the access credential API key of the interface. Click “Add Token” at the API token in the personal center, get the token key: sk-xxxxx and submit.

Step 2: Send Requests to Claude Opus 4.1

Select the “\**claude-sonnet-4-20250514\**” endpoint to send the API request and set the request body. The request method and request body are obtained from our website API doc. Our website also provides Apifox test for your convenience. Replace <YOUR_API_KEY> with your actual CometAPI key from your account. base url is Anthropic Messages format and Chat format.

Insert your question or request into the content field—this is what the model will respond to . Process the API response to get the generated answer.

Step 3: Retrieve and Verify Results

Process the API response to get the generated answer. After processing, the API responds with the task status and output data.

Features for Claude 4 Sonnet

Explore the key features of Claude 4 Sonnet, designed to enhance performance and usability. Discover how these capabilities can benefit your projects and improve user experience.

Pricing for Claude 4 Sonnet

Explore competitive pricing for Claude 4 Sonnet, designed to fit various budgets and usage needs. Our flexible plans ensure you only pay for what you use, making it easy to scale as your requirements grow. Discover how Claude 4 Sonnet can enhance your projects while keeping costs manageable.
Comet Price (USD / M Tokens)Official Price (USD / M Tokens)Discount
Input:$2.4/M
Output:$12/M
Input:$3/M
Output:$15/M
-20%

Sample code and API for Claude 4 Sonnet

Access comprehensive sample code and API resources for Claude 4 Sonnet to streamline your integration process. Our detailed documentation provides step-by-step guidance, helping you leverage the full potential of Claude 4 Sonnet in your projects.
Python
JavaScript
Curl
import anthropic
import os

# Get your CometAPI key from https://api.cometapi.com/console/token, and paste it here
COMETAPI_KEY = os.environ.get("COMETAPI_KEY") or "<YOUR_COMETAPI_KEY>"
BASE_URL = "https://api.cometapi.com"

message = anthropic.Anthropic(
    base_url=BASE_URL,
    api_key=COMETAPI_KEY,
)
messages = message.messages.create(
    model="claude-sonnet-4-20250514",
    max_tokens=1024,
    messages=[{"role": "user", "content": "Hello, Claude"}],
)
print(messages.content[0].text)

Python Code Example

import anthropic
import os

# Get your CometAPI key from https://api.cometapi.com/console/token, and paste it here
COMETAPI_KEY = os.environ.get("COMETAPI_KEY") or "<YOUR_COMETAPI_KEY>"
BASE_URL = "https://api.cometapi.com"

message = anthropic.Anthropic(
    base_url=BASE_URL,
    api_key=COMETAPI_KEY,
)
messages = message.messages.create(
    model="claude-sonnet-4-20250514",
    max_tokens=1024,
    messages=[{"role": "user", "content": "Hello, Claude"}],
)
print(messages.content[0].text)

JavaScript Code Example

import Anthropic from "@anthropic-ai/sdk";

// Get your CometAPI key from https://api.cometapi.com/console/token, and paste it here
const api_key = process.env.COMETAPI_KEY;
const base_url = "https://api.cometapi.com";

const anthropic = new Anthropic({
  apiKey: api_key,
  baseURL: base_url,
});

const message = await anthropic.messages.create({
  model: "claude-sonnet-4-20250514",
  max_tokens: 1024,
  messages: [{ role: "user", content: "Hello, Claude" }],
});
console.log(message.content[0].text);

Curl Code Example

curl https://api.cometapi.com/v1/messages \
     --header "Authorization: $COMETAPI_KEY" \
     --header "content-type: application/json" \
     --data \
'{
    "model": "claude-sonnet-4-20250514",
    "max_tokens": 1024,
    "messages": [
        {"role": "user", "content": "Hello, Claude"}
    ]
}'

Versions of Claude 4 Sonnet

The reason Claude 4 Sonnet has multiple snapshots may include potential factors such as variations in output after updates requiring older snapshots for consistency, providing developers a transition period for adaptation and migration, and different snapshots corresponding to global or regional endpoints to optimize user experience. For detailed differences between versions, please refer to the official documentation.
claude-sonnet-4-20250514
claude-sonnet-4-20250514-thinking
cometapi-sonnet-4-20250514
cometapi-sonnet-4-20250514

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