siteupdown.com
Help centre.
Plain-English answers about website errors, DNS, SSL, uptime and speed. Written to help you work out whether a site is down, and what to do next.
Error codes explained
What the numbers on an error page actually mean, and what to do about them.
Fix it from your side
Step-by-step checks for when a website will not load for you.
For website owners
SSL, DNS, domains, speed and uptime, in plain English.
How our checks work
What we measure, what the verdicts mean, and where the limits are.