Claude Opus 5.5 vs Sonnet 5.5: Which Is Better for Content Creation?

Most people pick one Claude model and use it for everything. Usually it’s the most powerful one they can get. If you’re paying for Opus, why would you write with anything else? Because for content, the answer to “Opus 5.5 or Sonnet 5.5?” is both, at different points in the work. I use Opus 5.5 to think and Sonnet 5.5 to create.

When I let Opus draft, the writing comes out over-engineered: titles that don’t land, caveats nobody asked for, warnings the reader doesn’t need. Sonnet writes the plainer draft. Opus does the work that decides whether the draft is worth writing at all. If you run your company’s content with AI, that split is the most useful model decision you can make right now.

Anthropic released Opus 5.5 on September 22 and Sonnet 5.5 six days later. The company is pretty clear that they’re for different work. It describes Opus 5.5 as “built for complex work requiring careful judgment.” Sonnet 5.5 is “strongest at well-scoped everyday tasks,” including “creating polished documents.” Opus 5.5 is a better writer than earlier…