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.
Frequently Asked Questions
1. Is it legal to use free OpenRouter models in commercial projects?
Yes, you can generally use free OpenRouter models in commercial projects, but you must follow both OpenRouter’s terms and each model provider’s license.
2. Do free models on OpenRouter have usage limits?
Yes, free models have strict rate limits (for example around 50–200 requests per day for new or free‑only users, with higher limits if you add credits).
3. What happens if a free OpenRouter model becomes paid?
If a free model switches to paid, your existing code still works but requests will start billing against your credits or may fail until you choose another free or paid model.
4. Which free OpenRouter models are best for coding vs chat?
For coding, power users often pick strong coder models like Qwen‑coder or Devstral‑style models, while for general chat and reasoning, DeepSeek, Llama, and Grok‑style chat models are popular free choices.
5. Can I rely on free models for production workloads?
Free models are great for testing and side projects, but their rate limits and potential instability usually make paid variants better for serious, production‑level traffic.