on demand

1. When needed or asked for, as in She's always ready to sing on demand, or Nowadays infants are generally fed on demand. This usage is a broadening of this phrase's meaning in finance, that is, “payable on being requested or presented,” as in This note is payable on demand. [Late 1600s]

Example Sentences

“If this synthetic blood substitute works, it could be absolutely game-changing because it can be freeze-dried, it can be reconstituted on demand, and it’s universal,” journalist Nicola Twilley says.

From Slate

Now, at last, some of the current hardy residents can experience joys such as hair straighteners on demand and not having to plan cups of tea.

From BBC

The series will be available to stream live and on demand on Paramount+.

From Los Angeles Times

A summary of each case will be published in advance to help the public understand the issues involved, and where appropriate, an "on demand" catch-up service will be available for those who can't watch the case in real time.

From BBC

“With GPT-5 now it’s like talking to an expert — a legitimate PhD-level expert in anything any area you need on demand ... whatever your goals are.”

From Los Angeles Times