Claude Sonnet 5 Launches — Near-Opus Performance at a Lower Price
Anthropic released Claude Sonnet 5 on June 30. It's not a new top-tier Opus — it's the next version of the mid-tier Sonnet line, and the headline of the announcement is simple: "performance approaching Opus 4.8, at a lower price." If you run token-heavy workloads like agents, this is a practical release, not just a benchmark update.
01. $2 per million input tokens until August 31
Launch pricing is $2 per million input tokens and $10 per million output tokens. That rate runs through August 31 — after that, Anthropic says it goes up to $3 input / $15 output.
For reference, Opus 4.8 sits at around $5 input / $25 output, so Sonnet 5 is an option for running the same workloads at a lower per-token cost. The promo window is only two months, so if you're planning a comparison run, this is the time to do it.
02. It's now the default model in Claude Code
In Claude Code, Sonnet 5 has become the default model. Per the official announcement, it ships with a native 1M-token context window, and you need Claude Code version 2.1.197 or later to access it.
A 1M-token context window is reportedly large enough to fit a substantial chunk of a codebase into a single prompt. That said, how it actually feels will depend on your project structure — this is one to verify hands-on.
03. "Matches Opus 4.8 at high effort" is the core claim
According to Anthropic's announcement, Sonnet 5 improves on the previous Sonnet 4.6 across reasoning, tool use, coding, and knowledge work — and when run at high effort, it matches Opus 4.8 on some tasks.
The announcement includes benchmarks like BrowseComp for agentic search and OSWorld-Verified for computer use. Keep in mind these numbers are all Anthropic's own measurements — real-world performance on your workload is something you'll need to check yourself.
04. It's the default for Free and Pro users too
Sonnet 5 is now the default model on the Free and Pro plans, and it's also available on Max, Team, Enterprise, and the API. The API model ID is claude-sonnet-5.
The practical takeaway: there's nothing to sign up for — it's available immediately in claude.ai and Claude Code. If running the heavier Opus for every task felt like overkill, you now have one more option to weigh on the cost-versus-performance scale.
Source: Anthropic — Claude Sonnet 5
This post summarizes the official announcement. It is not sponsored by Anthropic in any form.
Original with full infographics and visual structure: https://jessinvestment.com/claude-sonnet-5-launches-at-2-per-million-tokens-nearing-opus-performance/
Top comments (0)