Claude Opus Explained Simply

Claude Opus is Anthropic's most intelligent model, capable of complex reasoning, nuanced writing, and advanced coding tasks. While other models are fast, Opus is designed for depth.

This guide will walk you through exactly how to access it, set up your account, and get the most out of your first interaction.

Step 1: Create an Anthropic Account

To access Claude Opus, you'll need to go directly to the source.

Navigate to claude.ai.
Enter your email address or sign in with Google.
Complete the verification steps (email code and phone number verification may be required).

Note: Claude is available in many countries, but not everywhere yet. Check the supported list if you have trouble signing up.

Step 2: Upgrade to Claude Pro

Unlike the faster "Sonnet" model which is available for free, Claude Opus is currently a premium feature available only to Claude Pro subscribers.

Look for the "Upgrade to Pro" button in the profile menu or chat interface.
The subscription costs $20/month (plus applicable tax).
Enter your payment details to activate your subscription.

Why is it worth $20?

Access to Opus: The smartest model available.
Priority Access: Usage during high-traffic periods.
Early Access: Be the first to try new features.

Step 3: Selecting the Model

Once you are a Pro subscriber, you can switch between models depending on your needs.

Start a New Chat.
Look for the Model Selector dropdown (usually at the top left).
Select Claude 3 Opus.

Model Guide:

Opus: Complex coding, creative writing, analysis.

Sonnet: Daily tasks, quick questions.

Haiku: Extremely fast, lightweight tasks.

Step 4: Your First Prompt

Opus shines when you give it context. Don't just ask simple questions; give it a job.

Bad Prompt

"Write a poem about space."

Good Opus Prompt

"I want you to act as a cynical sci-fi author from the 1950s. Write a short, atmospheric poem about the silence of space, focusing on the isolation of a single cosmonaut. Use vivid imagery involving cold metal and distant stars."

Opus will pick up on the tone, style, and constraints much better than smaller models.

Step 5: For Developers (API Access)

If you are building an application (like this website!), you won't use the chat interface. Instead, you'll need the API.

Go to console.anthropic.com.
Sign up for a developer account.
Add credits (separate from the $20/mo chat subscription).
Generate an API Key.
Use the model ID claude-3-opus-20240229 in your code.

Frequently Asked Questions

Is there a free trial for Claude Opus? Currently, Anthropic does not offer a free trial for the Pro subscription. You get immediate access upon paying the first month's fee.

Can I use Opus on my phone? Yes! You can access claude.ai via your mobile browser, or download the official Claude app for iOS (and Android where available). Your Pro subscription carries over across all devices.

How does Opus compare to GPT-4? Opus often scores higher on benchmarks related to reasoning and coding. Many users find its writing style to be more natural and less "robotic" than GPT-4.