Cerebras Free Inference API: Web-Scale Chip Speed, Zero-Cost to Start
Cerebras Systems is known for its Web-Scale Engine (WSE) โ a wafer-scale processor built specifically to accelerate LLM inference. Its Inference API offers a free tier so you can experience some of the fastest open-model inference available today, at zero cost.
1. What the Free Tier Includes
| Item | Details |
|---|---|
| Free models | Llama 3.3 70B Instruct (main), Llama 3.1 8B |
| Output speed | Measured 1200โ2000 tokens/s (70B), far faster than typical GPU clusters |
| Context | 128K tokens |
| Rate limits | ~1 req/s, 60 req/min on the free tier (see console for live values) |
| Cost | $0, no credit card required |
Note: the Cerebras free tier is positioned for developer experience and evaluation โ great for prototyping and light production traffic, not for high-concurrency production workloads.
2. Sign Up & Get an API Key (~1 minute)
- Open the Cerebras console (console.cerebras.ai) and sign up with email or Google;
- Go to API Keys and create a key โ copy and store it safely;
- Try the built-in Playground on the console home page, no code needed.
No credit card, no enterprise verification.
3. API Call Examples
The Cerebras API is fully OpenAI-compatible โ just swap the base_url:
from openai import OpenAI
client = OpenAI(
base_url="https://api.cerebras.ai/v1",
api_key="YOUR_CEREBRAS_API_KEY",
)
resp = client.chat.completions.create(
model="llama-3.3-70b",
messages=[{"role": "user", "content": "Explain wafer-scale chips in one sentence"}],
max_tokens=256,
)
print(resp.choices[0].message.content)
cURL version:
curl https://api.cerebras.ai/v1/chat/completions \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{"model": "llama-3.3-70b", "messages": [{"role": "user", "content": "Hello"}], "max_tokens": 128}'
4. Rate Limits & Mitigation
- Rate-limited requests return
429with aRetry-Afterheader; - Implement exponential backoff (see our Unified API category for retry & fallback strategies);
- For high concurrency, route across Groq / Mistral free tiers โ APIShare's unified API has this built in.
5. Best Use Cases
- Rapid prototyping: 70B-class quality with second-level response times;
- Long-context streaming: 128K context + high throughput for real-time summarization and chat;
- Cost-sensitive light production: tool-style apps with modest daily request volume.
6. Comparison with Other Free Channels
| Channel | Representative model | Output speed (measured) | Context |
|---|---|---|---|
| Cerebras | Llama 3.3 70B | 1200โ2000 t/s | 128K |
| Groq | Llama 3.3 70B | 500โ1000 t/s | 128K |
| Mistral | Mistral Small | 300โ600 t/s | 32K |
| Cloudflare Workers AI | Llama 3.1 8B | 80โ150 t/s | 8K |
See our "2026 Free AI API Speed Ranking" for the full benchmark.
7. FAQ
Q: Can the free tier suddenly start charging me? A: Cerebras keeps free and paid keys strictly separated โ no silent billing.
Q: Does it support function calling?
A: Yes, the OpenAI-compatible tools parameter works as-is.
Q: Is commercial use allowed? A: Free-tier outputs are fine for development and evaluation; for production commercial use, upgrade to the paid tier for SLA guarantees.
๐ Get Started: One-Click Free API Access
Want to call all the free models above with a single API key, no need to sign up for each provider? Apishare.cc provides a unified API Key โ one key, 100+ models, free models at zero cost.
๐ Register on Apishare.cc โ Get your unified API Key
๐ Want to see more free model rankings? Check out the Sep 2026 Free LLM API Rankings โ
About the Free API Aggregator
The models covered in this guide are all served through the APIShare free API aggregator, which gives you one key for the whole catalog.
- Full model catalog: APIShare free API directory
- Sign up for a free trial key: Register and claim your API key