Is there a difference in performance between using the IP addresses 1.1.1.1 and the URL https://cloudflare-dns.com/dns?

Using the IP addresses 1.1.1.1 typically means using traditional DNS or DNS over TLS (if configured for that port). Using the URL https://cloudflare-dns.com/dns specifically enables DNS over HTTPS (DoH), which adds a layer of encryption. While both point to Cloudflare's DNS infrastructure, the performance difference is usually negligible, but DoH offers the added security benefit of encryption, which adds a minimal overhead.