Why Start Here?
Large Language Models are powerful, but getting started can feel overwhelming. This guide cuts through the noise: you'll pick a free API provider, paste in your key, and talk to an AI model — all in your browser.
⏱️ You'll have a working LLM call in under 10 minutes. No credit card required.
Get a Free API Key
All three providers offer free tiers — no credit card needed. Pick whichever appeals to you (you can always try the others later):
OpenRouter
Widest free model selection. Access Llama 3.3 70B, DeepSeek R1, Qwen3, Gemma 3, and Mistral Small 3.1 — all free. Great for exploring.
Get API Key →Groq
Blazing fast inference on custom LPU hardware. Free developer tier includes Llama 3.3 70B, Qwen3 32B, and GPT OSS 120B with generous rate limits.
Get API Key →Cerebras
The fastest inference available. Wafer-scale chips deliver incredible speed. Free tier includes all models: Llama 3.3 70B, Qwen3 32B, and GPT OSS 120B.
Get API Key →Your First LLM Call
Enter your API key above, type a message, and hit Send
Your API key never leaves your browser — all requests go directly from your browser to the provider's API. The key is only kept in memory and is automatically cleared when you leave or refresh the page.
Verify in source code ↗curl https://api.groq.com/openai/v1/chat/completions \
-H "Content-Type: application/json" \
-H "Authorization: Bearer YOUR_API_KEY" \
-d '{
"model": "llama-3.3-70b-versatile",
"messages": [{"role": "user", "content": "Hello, who are you?"}],
"temperature": 0.7,
"max_tokens": 256
}'Understanding the Response
choices[0].message.content
The actual text the model generated. This is what you'd show to a user.
usage.prompt_tokens / completion_tokens
How many tokens were used. Prompt tokens = your input, completion tokens = the model's output. This is how billing works (though free tiers don't charge).
finish_reason
"stop" means the model finished naturally. "length" means it hit the max_tokens limit and was cut off.
model
The exact model that processed your request. Some providers may route to different versions.
Your Learning Path
A curated roadmap from zero to advanced. Follow these topics in order for the best learning experience.
Learn the fundamentals of talking to AI models effectively
Understand how randomness controls creative vs. precise outputs
See how text gets broken into tokens the model understands
The building blocks behind every AI model
How models see and understand images
Run AI models on your own machine
Next Steps
Now that you've made your first LLM call, explore these topics to go deeper: