Source: https://uptimeify.io/resources/platform-and-support/glossary/downtime

# Downtime

> Downtime is any period during which a service is unavailable or not responding correctly to its users.

Downtime is the inverse of [uptime](/resources/platform-and-support/glossary/uptime). It includes hard outages (the server is unreachable) as well as soft failures: wrong HTTP status codes, content errors, or [response times](/resources/platform-and-support/glossary/response-time) so slow the service is effectively unusable.

Not all downtime is equal: a planned [maintenance window](/resources/platform-and-support/glossary/maintenance-window) is expected and usually excluded from SLA calculations, while unplanned downtime counts against your reliability targets and triggers incidents.