Wait for an amount of time

Return a promise that resolves after the given milliseconds.

JavaScriptNode.js & browsers Version 1.0.0 · MIT · .md

function wait(milliseconds) { return new Promise(resolve => setTimeout(resolve, milliseconds)); }

Usage

const started = performance.now();
await wait(50);
// At least ~50 ms later (timers can fire a millisecond early):
performance.now() - started >= 45; // → true

Lines marked → were executed in Node.js 22 and in headless Chromium, and each result was compared with the value shown. Lines marked e.g. are illustrative.

Know the limits

• setTimeout is a minimum delay, not a schedule: a busy event loop or a background tab can delay it much longer.
• Node.js ships the same: import { setTimeout as wait } from "node:timers/promises", which also accepts an AbortSignal.
• Typical use: await wait(retryAfterMs) before retrying a 429 or 503 response.

The function above is the code the usage lines run. It does not validate its arguments; add checks where it receives untrusted input.

Keep exploring

• Convert Celsius to Fahrenheit — Apply the temperature conversion without rounding the result.
• Convert hex to RGB — Expand #rgb if needed and read the red, green and blue channels.
• Convert URL parameters to object — Read a query string into an object; repeated keys become arrays.