15th October 2025
While Sonnet 4.5 remains the default [in Claude Code], Haiku 4.5 now powers the Explore subagent which can rapidly gather context on your codebase to build apps even faster.
You can select Haiku 4.5 to be your default model in /model. When selected, you’ll automatically use Sonnet 4.5 in Plan mode and Haiku 4.5 for execution for smarter plans and faster results.
— Catherine Wu, Claude Code PM, Anthropic
Recent articles
- Mr. Chatterbox is a (weak) Victorian-era ethically trained model you can run on your own computer - 30th March 2026
- Vibe coding SwiftUI apps is a lot of fun - 27th March 2026
- Experimenting with Starlette 1.0 with Claude skills - 22nd March 2026