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Free Claude 3.5 Sonnet API

Updated 7/2/2026

Free Claude 3.5 Sonnet API access via Vercel AI Gateway credits. Compare Anthropic-quality coding, 200K context, no-credit-card signup, and examples.

About the Model

Claude 3.5 Sonnet remains one of the most useful Anthropic models for coding, analysis, tool use, and careful writing. It is older than the latest Sonnet line, but still a practical free API target when you want Claude-style output without paying upfront.

Why choose it?

  • Coding strength: strong at refactors, explanations, and agentic development loops.
  • Long context: useful for reading larger files and documentation.
  • Low-friction free access: Vercel AI Gateway monthly credits let you test it without bringing an Anthropic key.

Free access option

  • Vercel AI Gateway: call anthropic/claude-3.5-sonnet through an OpenAI-compatible endpoint with monthly credits and no credit card required to start.

Choose Claude 3.5 Sonnet for coding-heavy prototypes, then compare the newer Claude Sonnet and Opus alternatives if you need higher capability.

How to call Claude 3.5 Sonnet

curl
curl https://ai-gateway.vercel.sh/v1/chat/completions \
  -H "Authorization: Bearer $AI_GATEWAY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"anthropic/claude-3.5-sonnet","messages":[{"role":"user","content":"Refactor this function into smaller pure functions."}]}'
python
from openai import OpenAI

client = OpenAI(base_url="https://ai-gateway.vercel.sh/v1", api_key="AI_GATEWAY_API_KEY")
response = client.chat.completions.create(
    model="anthropic/claude-3.5-sonnet",
    messages=[{"role": "user", "content": "Refactor this function into smaller pure functions."}],
)
print(response.choices[0].message.content)
javascript
import { generateText } from "ai";

const { text } = await generateText({
  model: "anthropic/claude-3.5-sonnet",
  prompt: "Refactor this function into smaller pure functions.",
});

console.log(text);

Provider Details

The following platforms provide free access to Claude 3.5 Sonnet through free tiers, trial credits, or daily quotas.

ProviderContext WindowFree QuotaRequires CCTrustAction
Vercel AI Gateway200KMonthly Credits
$5/mo
No
Trust 98
Details

Frequently Asked Questions

Is Claude 3.5 Sonnet free to use?

Yes. Claude 3.5 Sonnet is available for free through 1 provider(s) listed below, with no purchase required.

What are the rate limits and quotas?

Free access varies by provider — Vercel AI Gateway: Monthly Credits.

How do I get a free Claude 3.5 Sonnet API key?

Sign up with Vercel AI Gateway, then create an API key from your dashboard. See the provider details above for the exact steps.

Which providers offer Claude 3.5 Sonnet for free?

Claude 3.5 Sonnet is currently available for free via: Vercel AI Gateway.

Know another free provider for Claude 3.5 Sonnet?

Help the community by sharing other ways to access this model for free.