Claude Opus vs Sonnet: which is better for me?

For most people, Sonnet 4.6 is the smarter choice, and the benchmarks back it up: it scores around 79.6% on SWE-bench Verified, within roughly a point of Opus, at a fraction of the cost and with lower latency. That means for everyday coding, writing, and analysis, you get near-top quality with faster, cheaper responses, which is the definition of good value.

Opus 4.8 earns its place on the genuinely hard tasks: intricate reasoning, difficult debugging, complex multi-part instructions, and high-stakes documents where the last few percent of quality matters and a wrong answer is costly. On those, Opus's extra capability is worth the slower, pricier generation; on routine work, it is overkill.

The practical workflow is to make Sonnet your default and switch to Opus deliberately when a task defeats Sonnet or when the stakes justify the best. Many experienced users run almost everything on Sonnet and reserve Opus (and, for the very hardest long agentic jobs, Fable 5) for the exceptions.

On a Pro plan you have both, and the cost difference shows up as usage-budget consumption rather than a separate bill, so escalating when needed is easy. The skill is not paying for Opus everywhere; it is knowing when Sonnet is already enough.