Sonnet 5 Just Outscored Opus on Knowledge Work — at $2 a Million Tokens. Here's the Fine Print.
Anthropic's new default model scores 63.2% on SWE-bench Pro, beats Opus 4.8 on GDPval, and costs $2/$10 through August. But a new tokenizer inflates real costs up to 35%, and xhigh effort can erase the savings entirely. Here's the honest math.