The most important number in any AI model release is not a benchmark. It is how many people get the model without asking for it. By that measure, Claude Sonnet 5 is Anthropic’s biggest launch of the year: it is now the default model for every Free and Pro user.
Per Anthropic’s announcement, Sonnet 5 is available everywhere, from the consumer apps through Claude Code and the developer platform, with introductory API pricing running through August 31. The company positions it as an agentic workhorse: multi-step tasks and tool use at close to flagship capability, at a fraction of flagship cost.
Defaults are strategy
Model launches usually compete for enthusiasts. Default swaps compete for everyone else, the millions who never open a model picker. Pushing an agent-grade model to the free tier raises the floor of what casual users experience, and it sharpens the wedge Anthropic is driving into the developer market, where the credit war among model providers is already redefining customer acquisition. Introductory pricing on an already-cheaper tier reads the same way: get workloads onto Sonnet 5 before the discount window closes. Defaults cut the other way too, when the thing switched on by default is other people: Meta made every public account opt-in to AI remixing before pulling the Muse Image @-mention feature three days later.
What to watch
Watch what happens to usage caps and Pro subscription value as the default improves, whether rivals respond by upgrading their own free tiers, and where the introductory pricing lands after August 31. Defaults, caps and price are now the real battleground; benchmarks are the sideshow.
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