Is it down, or is it just you?
Ping a host, look up its DNS, read its HTTP headers, check its certificate or a port — from outside your network, in seconds. No sign-up, no installs.
Network tools, one at a time
Five tools run live from Cloudflare’s network. Traceroute and ICMP ping from Upzilla’s probe servers are on the way.
TCP ping
Connection time and loss to any host over IPv4 or IPv6.
→LiveDNS lookup
A, AAAA, CNAME, MX, TXT, NS, SOA and CAA records, or the PTR name of an address.
→LiveHTTP headers
Status codes, every redirect and the caching and security headers.
→LiveSSL check
Is the certificate accepted, and when does the newest one expire.
→LivePort check
Whether a TCP port is open, closed or filtered from outside.
→Traceroute & ICMP ping
Every hop to the destination, from Upzilla probe servers in several regions.
How to read a ping result
Three numbers tell you most of what you need.
time
Round-trip time in milliseconds. Under 50 ms is great for the same region; consistent spikes point to congestion or Wi-Fi trouble.
packet loss
The share of probes that never came back. Anything above 0% that persists deserves attention; 2%+ hurts real-time apps.
ttl
Time to live — how many hops a packet may still cross. It hints at the operating system and distance of the target.
Learn the numbers behind the tools
IPv4 vs IPv6 latency: why results can differ
The same host can respond at different speeds over IPv4 and IPv6. Here is why, and how to test both.
Read →GuidesHow to read traceroute output
Stars, repeated hops and sudden latency jumps explained, so you know which traceroute lines matter.
Read →BasicsPing vs traceroute: which one should you use?
Ping tells you whether a host answers. Traceroute tells you where the path slows down. Here is when to reach for each.
Read →Want to know before your users do?
Upzilla checks your websites, APIs and servers every minute and alerts you instantly.