Where to check free models
Check the OpenRouter Models page and look for models marked with :free. The free model list changes over time, so always verify before using.
How to create an API key
- Sign up or log in to OpenRouter.
- Go to your profile and open the API Keys section.
- Click Create Key and give it a name.
- Copy the key and store it safely.
- Use this header in all API requests:
Authorization: Bearer
Popular free models (examples)
x-ai/grok-4-fast:free
deepseek/deepseek-chat-v3.1:free
deepseek/deepseek-r1:free
zhipu-ai/glm-4.5-air:free
meta-llama/llama-4-maverick:free
qwen/qwen3-235b-a22b:free
Example request (cURL)
curl -X POST https://openrouter.ai/api/v1/chat/completions -H
“Content-Type: application/json” -H “Authorization: Bearer
” -d ‘{“model”:”deepseek/deepseek-r1:free”,”messages”
:[{“role”:”user”,”content”:”Hello”}],”max_tokens”:200}’
Example request (Python)
import requests
url = “https://openrouter.ai/api/v1/chat/completions”
headers = {
“Authorization”: “Bearer “,
“Content-Type”: “application/json”
}
data = {
“model”: “x-ai/grok-4-fast:free”,
“messages”: [{“role”: “user”, “content”: “Write a greeting”}],
“max_tokens”: 200
}
response = requests.post(url, headers=headers, json=data)
print(response.json())
Tips
- Free models can be busy. Try another if one fails.
- Always include :free in the model name.
- Never share your API key publicly.
- Use environment variables for production.
