Free tools

Small, free utilities for people who run websites: uptime math, and more on the way. No signup, no tracking beyond a page view.

• Uptime calculator

  Convert an SLA percentage into allowed downtime per day, week, month, and year.

• Downtime cost calculator

  What an hour of downtime costs at your revenue, and what a year at each uptime level adds up to.

• What is my IP

  Your public IP (IPv4 or IPv6), country, the edge that answered, and your HTTP and TLS versions. Nothing stored.

• Is my site down

  Check a site from outside - and past its CDN. A cache-busted second request catches origins hiding behind a cached 200.

• DNS lookup

  Ask Cloudflare and Google the same question at once. Matching answers mean your DNS change has landed; a split shows you where.