Simon Willison
Anthropic shipped a new "web search" feature for their Claude consumer apps today, here are my notes - it's frustrating that they don't share details on whether the underlying index is their own or run by a partner https://simonwillison.net/2025/Mar/20/claude-can-now-search-the-web/
Claude can now search the web

Claude 3.7 Sonnet on the paid plan now has a web search tool that can be turned on as a global setting. This was sorely needed. ChatGPT, Gemini and Grok …

Simon Willison’s Weblog
Mar 20, 2025 at 7:41pmWeb
Show threadSimon WillisonMar 21, 2025

It's using Brave as the search index, they quietly updated their "Trust Center" and added Brave Search as a subprocessor
https://simonwillison.net/2025/Mar/21/anthropic-used-brave/

https://bsky.app/profile/zugaldia.bsky.social/post/3lkvgzvarvs2s

Anthropic Trust Center: Brave Search added as a subprocessor

Yesterday I was [trying to figure out](https://simonwillison.net/2025/Mar/20/claude-can-now-search-the-web/) if Anthropic has rolled their own search index for Claude's new web search feature or if they were working with a partner. Here's …

Simon Willison’s Weblog
Show threadnickaltMar 21, 2025
@simon I'm surprised Brave is allowed to resyndicate their Bing search results like this.
Show threadAlex NedelcuMar 21, 2025

@nickalt Brave has its own index. It isn't using Bing.

@simon

Show threadPeter Bhat HarkinsMar 21, 2025
@simon This sounds a lot like Brave's practice where end users are mules to evade site controls of Brave's standard-defiant crawler: https://lobste.rs/s/iopw1d/what_s_up_with_lobste_rs_blocking_brave#c_xhmzzr
What's up with Lobste.rs blocking the Brave browser? | Lobsters

Show threadAlex NedelcuMar 21, 2025
@pushcx If you're referring to the browser informing Brave what to crawl, Chrome does the same thing for Google and it's opt-out (Brave's opt-in), meaning that after you login, Chrome starts sharing your browsing history to Google, with the declared purpose of improving search, even if you have an encryption password set. Google also uses that data for Gemini.
Show threadFeohMar 20, 2025

@simon That sounds like it might make Claude on par with ChatGPT in my guilty pleasure mode of using it to sate my nearly infinite curiousity for just about everything, but especially deep detail other people find meaningless :)

(Now if they'd just add an Advanced Voice Mode analogue :)

Show threadDanielMar 20, 2025

@simon Wouldn't it be awesome to have this working on top of an open search engine index like Marginalia?

https://www.marginalia.nu

I believe behind it is still just one person with servers in their basement but we can dream after all.

www.marginalia.nu

Marginalia is a website, not a person.

Show threadAaron MeurerMar 21, 2025
@djh @simon If they have an API you could do it yourself with an MCP server