How Long the Internet Remembers: 43.6 Billion DNS Answers, 40 Months of TTLs, and the Two Companies That Set the Cache Clock for a Third of the Web
We kept the exact TTL of every A record in 28 full crawls of the DomainsProject corpus, April 2023 to August 2026 — 43.6 billion DNS answers, 6.9 billion of them the address record of a registrable domain. The share of domains whose address expires in five minutes or less rose from 21.27% to 27.28%, and among live (non-parked) sites from 23.00% to 34.03%, almost all of it since March 2025. But 60.8% of surviving domains publish the same value 40 months later: GoDaddy's domaincontrol.com (mode 600) and Cloudflare (mode 300, 89% of its zones) set the number for a third of the web, and Cloudflare alone accounts for 47% of every domain at five minutes or less. For DNS and platform operators, SRE and incident-response teams, and Internet measurement researchers.