Which Claude Model Should You Use? (Haiku vs Sonnet vs Opus vs Fable)

Stop overpaying or burning through your usage limits by using the wrong AI model! In this tutorial, we break down Anthropic’s Claude models—Haiku, Sonnet, Opus, and Fable—so you can pick the exact right tool for every task. Learn the core rule of thumb for AI selection, how to switch models inside Claude, and why fixing your prompt is often better than upgrading your model. What You’ll Learn: Why choosing the largest model isn't always the best strategy When to use Haiku for quick, simple tasks Why Sonnet is your everyday go-to default When to upgrade to Opus for complex reasoning How Fable handles your most demanding AI workflows Prompt troubleshooting before switching models Timestamps: 0:00 - Introduction: Stop Using the Wrong Model 0:33 - Overview of Claude Models: Haiku, Sonnet, Opus & Fable 0:50 - How to Select a Model in Claude 1:00 - Haiku: Best for Quick & Simple Tasks 1:19 - Sonnet: The Everyday Default Model 1:35 - Opus: For Hard Problems & Complex Tasks 1:49 - Fable: High-Level Reasoning & Deep Research 2:02 - The #1 Mistake: Vague Prompts vs Model Size 2:16 - Quick Model Selection Cheat Sheet 2:34 - Why Claude Models Change & How to Find Missing Ones