How to Use Claude Sonnet 4.5 for Free (2026)

Claude Sonnet 4.5 is Anthropic's latest mid-tier model, offering an excellent balance between speed, intelligence, and cost. It excels at coding, analysis, and creative writing, often matching or exceeding GPT-4o on popular benchmarks. The Pro plan costs $20/month, but there are several legitimate ways to access Claude Sonnet 4.5 without paying.

This guide covers every free method available in 2026, their limitations, and what to do when you exhaust your free usage.

Method 1: Free Tier on claude.ai

Anthropic offers a free tier on claude.ai that includes access to Claude Sonnet 4.5.

Feature	Free	Pro ($20/mo)	Max ($100/mo)
Model	Claude Sonnet 4.5	Claude Sonnet 4.5 + Opus 4	All models, 20x usage
Daily messages	~15-30	~100+	~500+
Projects	Limited	Full	Full
Artifacts	Yes	Yes	Yes
File uploads	Yes (limited)	Yes	Yes
Extended thinking	No	Yes	Yes
Priority access	No	Yes	Yes

How to get started

Go to claude.ai and click "Sign Up."
Create an account with your email or Google account.
Verify your phone number (required for free accounts).
Start chatting -- Claude Sonnet 4.5 is the default model.

The free tier gives you approximately 15-30 messages per day, depending on message length and server load. Usage resets daily.

Tips to maximize free messages

Be concise. Shorter prompts use less of your daily allocation.
Use one long conversation. Continuing an existing conversation is more efficient than starting new ones.
Avoid large file uploads. Processing uploaded files consumes more of your usage limit.
Chat during off-peak hours. Free users get more generous limits when servers are less busy (typically late night and early morning US time).

Method 2: Anthropic API Free Credits

Anthropic provides free API credits when you create a new developer account.

What you get

$5 in free API credits upon account creation
Credits are valid for your first 30 days
Access to Claude Sonnet 4.5 and all other Claude models

Pricing context

With $5 in free credits, here is roughly how much usage you get with Claude Sonnet 4.5:

Usage Type	Approximate Amount
Input tokens	~1.6 million tokens ($3/1M input)
Output tokens	~330,000 tokens ($15/1M output)
Mixed conversations	~200-400 conversations

Setup

Go to console.anthropic.com and create an account.
Navigate to "API Keys" and generate a new key.
Your free credits are automatically applied.

import anthropic

client = anthropic.Anthropic(
    api_key="sk-ant-your-api-key"
)

message = client.messages.create(
    model="claude-sonnet-4-5-20250514",
    max_tokens=1024,
    messages=[
        {
            "role": "user",
            "content": "Explain the difference between REST and GraphQL APIs with examples."
        }
    ]
)

print(message.content[0].text)

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

const client = new Anthropic({
  apiKey: "sk-ant-your-api-key",
});

const message = await client.messages.create({
  model: "claude-sonnet-4-5-20250514",
  max_tokens: 1024,
  messages: [
    {
      role: "user",
      content: "Explain the difference between REST and GraphQL APIs with examples.",
    },
  ],
});

console.log(message.content[0].text);

Method 3: Free Access Through Third-Party Platforms

Several platforms provide free access to Claude Sonnet 4.5 as part of their own free tiers.

Cursor (Free Plan)

Cursor's free Hobby plan includes 50 fast premium requests per month that can use Claude Sonnet 4.5.

Download Cursor from cursor.com.
Create a free account.
Claude Sonnet 4.5 is available in the model selector for chat and inline edits.

Poe (Free Tier)

Poe by Quora gives free users daily access to Claude Sonnet 4.5 alongside other models.

Go to poe.com or download the app.
Create a free account.
Select "Claude-Sonnet-4.5" from the model list.
Free users get approximately 10-15 messages per day with premium models.

Amazon Bedrock Free Tier

If you have an AWS account, Amazon Bedrock offers Claude Sonnet 4.5 with a limited free trial.

Sign in to the AWS Console.
Navigate to Amazon Bedrock.
Request access to Anthropic Claude models.
New Bedrock users get a limited free trial period.

import boto3
import json

bedrock = boto3.client(
    service_name="bedrock-runtime",
    region_name="us-east-1"
)

response = bedrock.invoke_model(
    modelId="anthropic.claude-sonnet-4-5-20250514-v1:0",
    body=json.dumps({
        "anthropic_version": "bedrock-2023-05-31",
        "max_tokens": 1024,
        "messages": [
            {
                "role": "user",
                "content": "Write a Python decorator that retries a function up to 3 times on failure."
            }
        ]
    })
)

result = json.loads(response["body"].read())
print(result["content"][0]["text"])

Google Vertex AI

Claude Sonnet 4.5 is also available through Google Cloud's Vertex AI, which offers $300 in free credits for new accounts.

Method 4: Free via Open-Source Interfaces

Several open-source tools let you use your free API credits through better interfaces.

TypingMind

TypingMind is a one-time purchase frontend for AI APIs. Bring your own Anthropic API key (with free credits) and get a better chat interface with features like prompt library, conversation folders, and plugins.

Open WebUI

Open WebUI is a free, self-hosted chat interface that works with Claude API.

docker run -d -p 3000:8080 \
  -e ANTHROPIC_API_KEY=sk-ant-your-key \
  --name open-webui \
  ghcr.io/open-webui/open-webui:main

Claude Sonnet 4.5 vs. Free Alternatives

If you run out of free Claude access, these alternatives are also free:

Model	Free Access	Best For	Compared to Claude Sonnet 4.5
GPT-4o (ChatGPT)	15-20 msg/3hr	General tasks	Similar quality, different style
Gemini 2.0 Flash	Generous free tier	Speed, multimodal	Faster but less nuanced
Grok 4 Mini	10 msg/day on X	Real-time info	Less capable overall
Llama 3.3 70B	Free on Groq	Open-source fans	Good but slightly behind
DeepSeek V3	Free on deepseek.com	Coding, math	Strong at code, less polished

Frequently Asked Questions

How many free messages do I get on claude.ai per day? Approximately 15-30, depending on message length and server load. The exact number varies and is not publicly documented by Anthropic.

Is Claude Sonnet 4.5 the same as Claude 4.5 Sonnet? Yes. The naming convention is "Claude [version] [tier]" -- so Claude Sonnet 4.5 and Claude 4.5 Sonnet refer to the same model.

Can I use Claude Sonnet 4.5 for free commercially? The free tier on claude.ai is subject to Anthropic's terms of service. For commercial use, the API is more appropriate, and you pay per token.

What is the difference between Claude Sonnet 4.5 and Claude Opus 4? Opus 4 is Anthropic's most capable model, excelling at complex reasoning, long-form writing, and nuanced tasks. Sonnet 4.5 is faster, cheaper, and nearly as capable for most use cases.

Does the free tier support file uploads and vision? Yes. Free users can upload images and documents to Claude on claude.ai.

Wrapping Up

Claude Sonnet 4.5 is one of the best language models available, and you do not need to pay to use it. Between the free tier on claude.ai, API credits for developers, and third-party platform access through Cursor, Poe, and cloud providers, you can get substantial free usage.

If you are building applications that need AI-generated media like images, videos, or realistic talking avatars, try Hypereal AI free -- 35 credits, no credit card required. It complements Claude's text capabilities with powerful media generation APIs.