Chat with Phi 4

[Microsoft Research](/microsoft) Phi-4 is designed to perform well in complex reasoning tasks and can operate efficiently in situations with limited memory or w

No signup required — try it as a guest. 30,000 free tokens every day once you sign up.

Provider
Microsoft
Model slug
microsoft/phi-4
Typical cost
Around 103–258 tokens per typical message. 15M Pro tokens buy roughly 58,139–145…
Availability
On Faceb.ai · chat + API

About Phi 4

[Microsoft Research](/microsoft) Phi-4 is designed to perform well in complex reasoning tasks and can operate efficiently in situations with limited memory or where quick responses are needed. At 14 billion...

What it's good at

1

16,384-token context window.

2

Extremely low per-token price compared to frontier models — good for high-volume workloads.

3

Hosted by Microsoft — you can access it here alongside GPT-4o, Claude, Gemini and 100+ more on one plan.

4

Switch to any other model mid-conversation from the picker.

Pricing on Faceb.ai

Around 103–258 tokens per typical message. 15M Pro tokens buy roughly 58,139–145,631 messages.

Use Phi 4 from the API

OpenAI-compatible. Same Faceb.ai tokens cover chat and API. Drop-in replacement for the OpenAI SDK.

curl https://api.faceb.ai/v1/chat/completions \
  -H "Authorization: Bearer sk-faceb-YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "microsoft/phi-4",
    "messages": [{"role": "user", "content": "Hello!"}],
    "stream": true
  }'
from openai import OpenAI

client = OpenAI(
    base_url="https://api.faceb.ai/v1",
    api_key="sk-faceb-YOUR_KEY",
)

stream = client.chat.completions.create(
    model="microsoft/phi-4",
    messages=[{"role": "user", "content": "Hello!"}],
    stream=True,
)
for chunk in stream:
    print(chunk.choices[0].delta.content or "", end="", flush=True)
import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://api.faceb.ai/v1",
  apiKey: "sk-faceb-YOUR_KEY",
});

const stream = await client.chat.completions.create({
  model: "microsoft/phi-4",
  messages: [{ role: "user", content: "Hello!" }],
  stream: true,
});
for await (const chunk of stream) {
  process.stdout.write(chunk.choices[0]?.delta?.content || "");
}

Also works for image generation (image-output model slugs return image_url content parts) and web search (add "web_search": true to the payload). Same endpoint, same wallet.

Full API docs → · Get an API key →

Frequently asked — Phi 4

What is Phi 4?

Phi 4 is a chat/completion model served by Microsoft and accessed through Faceb.ai. Try it without signing up — guest users get a small pool of session tokens to experiment.

Is Phi 4 free on Faceb.ai?

You get 30,000 tokens free every day — usually enough for a handful of messages a day on this model. Need more? Pro is $14.99/month for 15M tokens, or top-ups from $5.

What's Phi 4's context window?

16,384 tokens. Paste your source material in, no need to truncate.

Can I call Phi 4 from the API?

Yes. Any API key from /account/api/ works with model slug `microsoft/phi-4`. The OpenAI SDK works with base_url=https://api.faceb.ai/v1.

How does Phi 4 compare to GPT-4o or Claude?

Depends on the task. Faceb.ai lets you switch models per message — benchmark side-by-side by asking both the same prompt, which is more reliable than abstract comparisons.

How much does Phi 4 cost per message here?

Around 103–258 tokens per typical message. 15M Pro tokens buy roughly 58,139–145,631 messages.

Does Faceb.ai train on my Phi 4 prompts?

No. We contractually request that upstream providers not train on content routed through us. Your chat history lives only on your account.

Is Phi 4 good for coding?

It depends on the model size and training mix. For serious code work the developer favourites are Claude 3.5 Sonnet and DeepSeek V3; for quick edits, most capable models work fine.

Can I use Phi 4 on the API with the OpenAI SDK?

Yes — point your SDK at https://api.faceb.ai/v1 and use this model's slug as the model parameter. Everything else works as normal.

Does Phi 4 support image inputs?

Check the model catalog — multimodal models are marked in the picker. If it accepts images, you can drop screenshots and diagrams straight into the chat.

Can I switch from Phi 4 to another model mid-chat?

Yes — the picker is always at the top of the chat. Previous context carries over.

Will newer versions of Phi 4 show up here automatically?

Yes. Our catalog auto-fetches from the upstream aggregator, so provider updates and new versions appear in the picker as soon as they're available.

Or try a different model

Your Faceb.ai tokens work for every model — switch per message, no extra subscriptions.

Ready to chat?

One subscription covers every frontier model — switch between them per message. No extra API keys, no extra bills.

Start chatting with Phi 4 → Go Pro · $14.99/mo