Simon Willison’s Weblog


Claude 3.5 Sonnet. Anthropic released a new model this morning, and I think it's likely now the single best available LLM. Claude 3 Opus was already mostly on-par with GPT-4o, and the new 3.5 Sonnet scores higher than Opus on almost all of Anthropic's internal evals.

It's also twice the speed and one fifth of the price of Opus (it's the same price as the previous Claude 3 Sonnet). To compare:

  • gpt-4o: $5/million input tokens and $15/million output
  • Claude 3.5 Sonnet: $3/million input, $15/million output
  • Claude 3 Opus: $15/million input, $75/million output

Similar to Claude 3 Haiku then, which both under-cuts and out-performs OpenAI's GPT-3.5 model.

In addition to the new model, Anthropic also added a "artifacts" feature to their Claude web interface. The most exciting part of this is that any of the Claude models can now build and then render web pages and SPAs, directly in the Claude interface.

This means you can prompt them to e.g. "Build me a web app that teaches me about mandelbrot fractals, with interactive widgets" and they'll do exactly that - I tried that prompt on Claude 3.5 Sonnet earlier and the results were spectacular (video demo).

An unsurprising note at the end of the post:

To complete the Claude 3.5 model family, we’ll be releasing Claude 3.5 Haiku and Claude 3.5 Opus later this year.

If the pricing stays consistent with Claude 3, Claude 3.5 Haiku is going to be a very exciting model indeed.