# uptime

CEFR B2 · Noun

Source: https://englishreference.com/word/uptime
Updated: 2026-07-22

## Definition

the amount of time a computer, machine, or website is working and available to use. It is usually shown as a percentage.

For teachers: the period during which a computer system, network, or piece of machinery is operational and available for use. Often expressed as a percentage of total time to measure reliability.

## Examples

- The server has had 100% uptime this month.
- Cloud service providers often guarantee a specific level of uptime in their contracts to reassure business clients.
- While scheduled maintenance is necessary for security, excessive downtime can lead to significant revenue loss, making high uptime a critical metric for any e-commerce platform.

## Usage notes

- Typically used in technical or business contexts; often contrasted with 'downtime'.

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