Chat with Claude 3.5 Sonnet

Anthropic's best balance of quality and cost — a coder favourite.

No signup required — 10,000 session credits for guests. 50,000 free credits on account creation.

Provider
Anthropic
Model slug
anthropic/claude-3.5-sonnet
Typical cost
Around 3,750–7,500 credits per typical message. 15M Pro credits buy ~2,000–4,000…
Availability
On Faceb.ai · chat + API

About Claude 3.5 Sonnet

Claude 3.5 Sonnet is Anthropic's best everyday model — consistently ranked top-tier for code, reasoning, and long-form writing. 200k context (paste entire codebases), careful tone, and refreshingly honest uncertainty.

What it's good at

1

State-of-the-art code generation — especially refactoring

2

200k context (largest of the frontier models)

3

Careful, calibrated tone — less over-confident than GPT-4o

4

Excellent at following detailed system prompts

Pricing on Faceb.ai

Around 3,750–7,500 credits per typical message. 15M Pro credits buy ~2,000–4,000 Sonnet messages.

Frequently asked — Claude 3.5 Sonnet

What is Claude 3.5 Sonnet?

Claude 3.5 Sonnet is Anthropic's mid-size flagship — released June 2024. It replaced Claude 3 Opus as their best everyday model and powers most of the coding-tooling market (Cursor, Windsurf, many agents).

Is Claude 3.5 Sonnet better than GPT-4o for code?

Most developers think so — Sonnet has been the default coding model on Cursor and Windsurf for months. It's especially strong on refactors and understanding existing codebases.

Can I chat with Claude without a Claude.ai subscription?

Yes. Faceb.ai gives you Sonnet alongside GPT-4o, Gemini and 100+ more on one $14.99/month plan — no Anthropic sub required.

Does Claude 3.5 Sonnet support image input?

Yes, natively. Drop a screenshot and it reads it.

What's the context window?

200,000 tokens — larger than GPT-4o's 128k. Enough to paste entire medium-size codebases.

How much does a Sonnet message cost in credits?

Around 3,750–7,500 credits for a typical exchange. 15M Pro credits buy roughly 2,000–4,000 Sonnet messages.

Does Claude hallucinate less than GPT-4o?

Anecdotally yes — Anthropic's training emphasises calibrated uncertainty. It's more willing to say "I don't know" or flag a guess.

Is there a Claude Opus or Haiku option too?

Yes — the picker has Claude 3 Haiku (fastest/cheapest Anthropic) and Claude 3 Opus (larger, pricier). Switch per message.

Can I call Claude 3.5 Sonnet from the API?

Yes. Your API keys work with any model slug — use anthropic/claude-3.5-sonnet with the OpenAI SDK pointed at https://api.faceb.ai/v1.

What's Sonnet's knowledge cutoff?

Roughly April 2024 for the current version — it gets refreshed occasionally.

Does Claude 3.5 Sonnet do tool-use / function calling?

Yes — Anthropic's tool-use API is supported. Your client library just needs to pass the tools list in the request.

Is my prompt private when I use Claude on Faceb.ai?

We don't store prompts beyond your chat history, and we don't train on them. Anthropic's policy prohibits training on API traffic.

Or try a different model

Your Faceb.ai credits 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 Claude 3.5 Sonnet → Go Pro · $14.99/mo