Uptime

Uptime is the time a website or server ✕ A server is a powerful computer that provides data or services to other devices — for example serving a website or storing your cloud files. More in the glossary → is reliably online and reachable, usually given as a percentage over a period. Its counterpart is "downtime," when the site is unavailable. In hosting ✕ Web hosting is renting space on a server so your website is reachable around the clock. The host takes care of the technology, security, and availability. More in the glossary → , uptime is a key quality measure: even small differences matter — 99.9% means about 8–9 hours of outage per year, while 99.99% is only around 50 minutes. Reputable providers offer an uptime guarantee. See which hosts offer the best availability in the best web hosting comparison.