How much does Claude Sonnet 4 cost?

Claude Sonnet 4 is billed pay-as-you-go at $0.45 per 1M input tokens and $2.25 per 1M output tokens. There is no subscription — you only pay for what you use.

What is the context window of Claude Sonnet 4?

Claude Sonnet 4 supports a context window of up to 200K tokens. It can return up to 64K tokens in a single response.

What can Claude Sonnet 4 do?

Claude Sonnet 4 supports Vision, Tool calling, Reasoning, Documents, Prompt caching.

Is Claude Sonnet 4 free to use?

Claude Sonnet 4 is a paid, pay-as-you-go model — no subscription, you are only charged for usage.

How do I use Claude Sonnet 4 via the API?

Claude Sonnet 4 is OpenAI-compatible. Point any OpenAI SDK at https://api.airforce/v1 and pass the model ID claude-sonnet-4-20250514 with your Api.Airforce API key.

Who makes Claude Sonnet 4?

Claude Sonnet 4 is Anthropic's chat model, served through the unified Api.Airforce gateway alongside 100+ other models.

AnthropicPaidOperational

Claude Sonnet 4

API model name: claude-sonnet-4-20250514

Claude Sonnet 4 is Anthropic's chat model, served on the Api.Airforce unified API. It has a 200K-token context window. Beyond text, it accepts image, document as input. Capabilities include Vision, Tool calling, Reasoning, Documents, Prompt caching. It is priced at $0.45 per million input tokens and $2.25 per million output tokens. Knowledge cutoff: 2025-04. Access it through the OpenAI-compatible API with one key, alongside 100+ other models on Api.Airforce.

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Pricing

Input / 1M tokens

$0.45

Output / 1M tokens

$2.25

Cache read / 1M tokens

$0.06

Cache write / 1M tokens

$0.57

Specifications

Provider: Anthropic
Type: chat model
Context window: 200K tokens
Max output: 64K tokens
Knowledge cutoff: 2025-04
Input: text, image, document
Output: text
Prompt caching: Supported

Capabilities

VisionTool callingReasoningDocumentsPrompt cachingStreaming

What is Claude Sonnet 4 used for?

Chatbots & assistants — conversational AI, drafting, summarizing and Q&A.
Image understanding — analyze photos, screenshots, charts and scanned documents.
Agents & automation — function calling and tool use for multi-step workflows.
Complex reasoning — math, coding and step-by-step problem solving.
Document analysis — summarize and answer questions across long files.
Long-context tasks — process entire documents or codebases in a single prompt.
Real-time experiences — stream tokens for responsive chat and apps.

Claude Sonnet 4 vs. similar models

Model	Intelligence	Context	Input / 1M	Output / 1M
Claude Sonnet 4	—	200K	$0.45	$2.25
Claude Haiku 4.5	—	200K	$0.30	$1.80
Claude Opus 4	—	—	$2.25	$11.25
Claude Opus 4.1	—	—	$2.25	$11.25

Prices are Api.Airforce pay-as-you-go rates per 1M tokens. Context is the maximum input length.

Claude Sonnet 4 — frequently asked questions

How much does Claude Sonnet 4 cost?: Claude Sonnet 4 is billed pay-as-you-go at $0.45 per 1M input tokens and $2.25 per 1M output tokens. There is no subscription — you only pay for what you use.
What is the context window of Claude Sonnet 4?: Claude Sonnet 4 supports a context window of up to 200K tokens. It can return up to 64K tokens in a single response.
What can Claude Sonnet 4 do?: Claude Sonnet 4 supports Vision, Tool calling, Reasoning, Documents, Prompt caching.
Is Claude Sonnet 4 free to use?: Claude Sonnet 4 is a paid, pay-as-you-go model — no subscription, you are only charged for usage.
How do I use Claude Sonnet 4 via the API?: Claude Sonnet 4 is OpenAI-compatible. Point any OpenAI SDK at https://api.airforce/v1 and pass the model ID claude-sonnet-4-20250514 with your Api.Airforce API key.
Who makes Claude Sonnet 4?: Claude Sonnet 4 is Anthropic's chat model, served through the unified Api.Airforce gateway alongside 100+ other models.

All models·Quickstart·Chat API reference

Use Claude Sonnet 4 via the API

OpenAI-compatible — point any OpenAI SDK at https://api.airforce/v1 and pass claude-sonnet-4-20250514 as the model.

cURL

curl https://api.airforce/v1/chat/completions \
  -H "Authorization: Bearer $AIRFORCE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-sonnet-4-20250514",
    "messages": [{ "role": "user", "content": "Hello!" }]
  }'

Python

from openai import OpenAI
client = OpenAI(base_url="https://api.airforce/v1", api_key="$AIRFORCE_API_KEY")
r = client.chat.completions.create(
    model="claude-sonnet-4-20250514",
    messages=[{"role": "user", "content": "Hello!"}],
)
print(r.choices[0].message.content)

JavaScript

import OpenAI from "openai";
const client = new OpenAI({ baseURL: "https://api.airforce/v1", apiKey: process.env.AIRFORCE_API_KEY });
const r = await client.chat.completions.create({
  model: "claude-sonnet-4-20250514",
  messages: [{ role: "user", content: "Hello!" }],
});
console.log(r.choices[0].message.content);