Definition
DoH (DNS over HTTPS) encrypts DNS queries by sending them as HTTPS requests instead of plaintext UDP. Traditional DNS queries are unencrypted and visible to ISPs and network observers. DoH prevents this. Cloudflare (1.1.1.1), Google (8.8.8.8), and others provide DoH endpoints. Browsers like Firefox and Chrome can use DoH directly, bypassing the OS resolver.
Use the tool: DNS Benchmark — check doh for any domain.