F.3 — Models and plans

Front matter — Level 0. Product details verified on 02/07/2026 against official sources.

Goal

By the end you will be able to distinguish the families of Claude models and understand what each plan unlocks, so you can choose the right combination for you. The specific figures here are volatile: the criteria matter more than the numbers.

The three model families

Claude offers three main families, designed for different balances of intelligence, speed and cost. The name stays (Opus, Sonnet, Haiku), the version number changes over time.

Table F.3.1 — The families and the current version.

In short: Opus is the most capable, suited to difficult tasks and long agentic work; Sonnet is the ideal balance between output and speed, the “everyday” choice (and the model proposed by default on the Free and Pro plans); Haiku is the fastest, perfect for short answers and simple tasks.

Above Opus there’s a class of more powerful models (the “Mythos”), designed for the most extreme reasoning and agentic work: Fable 5 (a version made more widely available) and Mythos 5 (with restricted access). Their recent history alone explains why this book thinks in terms of families: launched in June 2026, they were suspended after three days by a government directive, then reactivated three weeks later, when the directive was lifted. And the return came with its own conditions: Fable 5 is included in paid plans only in part and for a limited period, after which you use it through usage credits (ch. L6.4); it has stricter safeguards than the other models, which sometimes block legitimate requests; and its data follows different retention rules. The moral: flagship models come and go, and each arrives with its own rules. For the current status, refer to the companion repo and the official sources.

Warning: the names, strings and even the availability of the models change frequently. Don’t memorize a model as “the right one forever”: verify the current version when you need it.

How to choose the model

A practical rule that survives version changes: start from Sonnet. If the answer can’t handle the complexity of the task, move up to Opus. If you only need speed on something simple, drop down to Haiku. Don’t pick the most powerful model “just to be safe”: you often pay more without any benefit.

The plans

The plan determines which products you can access and how much you can use them. Beyond the chat, each level adds something.

Table F.3.2 — What each plan unlocks.

The Free plan covers the chat, web search, file creation, Skills and up to five Projects well, but it doesn’t include Code, Cowork or Design. Pro is the watershed: it unlocks exactly those three. Max doesn’t add products but raises the usage limits considerably. Team and Enterprise add administration, security and centralized management for organizations.

Note: the indicative prices (in USD) were, as of June 2026, around $17-20/month for Pro and from ~$100/month for Max. These are volatile figures: check the up-to-date value at claude.com/pricing.

Common mistakes

• Choosing Free to use Code or Cowork. They’re not enough: you need at least Pro.
• Paying for Max without needing it. Max is for usage limits, not for unlocking new products: if you don’t hit Pro’s limits, you don’t need it.
• Fixing on a model name. Versions change; think in terms of families.

Summary

1. Three families: Opus (power), Sonnet (balance), Haiku (speed).
2. Start from Sonnet; move up to Opus if needed, drop down to Haiku for simple tasks.
3. Free doesn’t include Code, Cowork and Design; Pro does.
4. Max raises usage limits; Team/Enterprise add management and security.
5. Prices and versions are volatile: verify against official sources.

Next step

In ch. F.4 — Reading paths you’ll choose where to start the book based on what you need, with three ready-made itineraries.