window.setTimeout() sets a timer that runs a function once after the delay expires (MDN). It returns a timeout ID — pass that ID to clearTimeout() to cancel. For repeating calls, use setInterval().
Pass the required arguments shown below. Check return values and browser support before you rely on the result.
Call window.setTimeout. Start with this line.
setTimeout(fn, delay, ...args)| Call | What it does |
|---|---|
setTimeout(fn, delay, ...args) | Primary signature. |
window.setTimeout(...) | Call with the arguments your case needs. |
Built into the browser. Call window.setTimeout(...) (or the global setTimeout(...)) — no import required.
setTimeout(fn, delay, ...args)| Parameter | Description |
|---|---|
| func | Required. Function to run once after the delay |
| delay | Optional. Milliseconds to wait (default 0) |
| param1…N | Optional. Forwarded to func when it runs |
| Return Value | Description |
|---|---|
| * | Pass to clearTimeout() |
MDN: schedule a callback that runs once when the timer expires.
const id = setTimeout(function () {
console.log("Hello after 2 seconds");
}, 2000);
// optional: clearTimeout(id);setTimeout registers the callback.clearTimeout(id) before it fires.MDN: arguments after delay are forwarded to the callback.
function greet(name) {
console.log("Hello, " + name);
}
setTimeout(greet, 1000, "Alex");
// or: setTimeout(() => greet("Alex"), 1000);greet expects a name."Alex" is passed when it runs.clearTimeoutMDN: cancel the timer before the callback runs.
const id = setTimeout(function () {
console.log("You will not see this if canceled");
}, 3000);
clearTimeout(id);
console.log("Canceled");clearTimeout(id) removes it.MDN: shorter delays finish first; code after setTimeout runs immediately.
console.log("A: start");
setTimeout(() => console.log("B: after 0ms"), 0);
console.log("C: after schedule");
// Typical order: A, C, then Bdelay: 0 queues for the next turn.B runs after the current stack finishes.setTimeout vs setIntervalOne runs once; the other repeats until cleared.
setTimeout(() => console.log("timeout once"), 1000);
const i = setInterval(() => console.log("interval"), 1000);
// later: clearInterval(i);setTimeout after work finishes if the delay must wait on completion.Window.setTimeout() is marked Baseline Widely available on MDN (since July 2015). It is not Deprecated, Experimental, or Non-standard. Available in browsers and workers; prefer function callbacks over string code.
Run a callback once after a delay across modern browsers.
Bottom line: Universal timer API. Store the ID to cancel; avoid string code; remember delays can be longer under load.
Stop the browser from loading the current document.
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