Claude Sonnet 5
The balanced workhorse of the Claude 5 family.
Strong coding performance at a meaningfully lower cost than Opus, which makes it the sensible default for routine feature work, refactors, and tests. Most people should start here and escalate only when they hit a wall.
Best for
The great majority of day-to-day coding work.
Watch out for
On genuinely hard problems, escalating to Opus is cheaper than three failed Sonnet attempts.
Using this and stuck anyway?
Knowing the tool isn't the same as finishing the project. If yours has stopped moving, we'll take a look at it.
Tell us what's broken