Anthropic launches Claude Sonnet 5 at a steep discount to its top model as the company races toward a blockbuster IPO
Why this matters: a development in AI with implications for how people work, create, and decide.
Anthropic today released Claude Sonnet 5, a new AI model that the company says delivers near-flagship performance at mid-tier prices — a move designed to give cost-conscious enterprise developers access to powerful agentic capabilities just as the San Francisco-based AI lab barrels toward an initial public offering that will test whether the private market's staggering AI valuations can survive public scrutiny.The release, which Anthropic describes as "the most agentic Sonnet model yet," makes Sonnet 5 the default model for users on Anthropic's Free and Pro plans, while also making it available to Max, Team, and Enterprise customers. Introductory API pricing is set at $2 per million input tokens and $10 per million output tokens through August 31, after which it rises to $3 and $15 respectively — still well below the $5 input and $25 output pricing of Anthropic's top-of-the-line Opus 4.8.The strategic logic is unmistakable: Anthropic is trying to democratize access to capabilities that until very recently only its most expensive models could deliver, while building the kind of broad-based developer adoption that will look attractive in an S-1 filing.Sonnet 5 benchmarks show the mid-tier model closing in on Anthropic's flagship OpusSonnet 5 posts major gains over its predecessor, Sonnet 4.6, across every evaluation Anthropic disclosed. On SWE-bench Pro, an agentic coding benchmark, Sonnet 5 scores 63.2% compared with Sonnet 4.6's 58.1% — a jump that brings it within striking distance of Opus 4.8's 69.2%. On Terminal-Bench 2.1, another coding evaluation, the gap narrows further: 80.4% for Sonnet 5 versus 67.0% for Sonnet 4.6 and 82.7% for Opus 4.8.In multidisciplinary reasoning, as measured by Humanity's Last Exam, Sonnet 5 scores 43.2% without tools and 57.4% with tools — the latter figure essentially matching Opus 4.8's 57.9%. On computer use tasks evaluated through OSWorld-Verified, Sonnet 5 reaches 81.2%, up from 78.5%. And