Anthropic just made its most agentic Sonnet the free default
Anthropic just made its most agentic Sonnet the free default. On 30 June, Anthropic made Claude Sonnet 5 — its most agentic Sonnet yet — the default model for every Free and Pro user, with performance close to flagship Opus 4.8 at introductory pricing through 31 August that undercuts what Sonnet 4.6 cost.
What it actually means
This is a free-tier upgrade, not a paid perk. Sonnet 5 finishes multi-step jobs — plans the work, drives a browser or terminal, checks its own output — that used to stall or need the pricier Opus model. If you've been paying for Opus because Sonnet felt shallow, that gap just closed, and the introductory price undercuts what you paid for Sonnet 4.6. Skip the benchmark chart and run the test yourself: take one task you've been routing to a bigger model and hand it to Sonnet 5 this week. You may not need the upgrade you were paying for.
The gap between the model you get for free and the one you paid extra for just narrowed to almost nothing.
31 Augwhen Sonnet 5's introductory pricing ends
Source: Anthropic · Sunday, 5 July 2026