Let me be upfront about something: this tutorial will age badly. Not the concepts — those hold. But the specific names, the price points, the rankings — the AI model landscape moves fast enough that any comparison table has an expiration date. What's the best model for code today might be second place next quarter. The one that seems expensive now might be the obvious choice by the time you're reading this.
That said: the mental model for navigating this landscape doesn't expire. What questions to ask when choosing a model, how API access differs from a subscription, what "context window" actually means on a regular Tuesday — that's stable. With the right map, you can update yourself when things change. And they will.
The frontier models: the big three
Frontier models are the most capable models at any given moment. In 2026, the competition comes down to three:
Claude Sonnet 4.6 (Anthropic) is the model you'll be using throughout this course, and the current benchmark for coding tasks. Together with Opus 4.7, it ships with a 1M token context window at standard pricing — no special headers, no premium plan required. It stands out for sustained reasoning, precise technical writing, and following complex multi-step instructions. Sonnet 4.6 is the speed-quality balance; Opus 4.7 is more powerful but slower and more expensive.
