Simon Willison’s Weblog

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22nd March 2026

Tool DNS Lookup

TIL that Cloudflare's 1.1.1.1 DNS service (and 1.1.1.2 and 1.1.1.3, which block malware and malware + adult content respectively) has a CORS-enabled JSON API, so I had Claude Code build me a UI for running DNS queries against all three of those resolvers.

This is a beat by Simon Willison, posted on 22nd March 2026.

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