# How to use window.confirm()

> Learn how to use the browser confirm() method to show a confirmation dialog that blocks the script and returns true or false based on the OK or Cancel button.

Author: [Flavio Copes](https://flaviocopes.com/about/) | Published: 2021-04-08 | Topics: [JavaScript](https://flaviocopes.com/tags/js/) | Canonical: https://flaviocopes.com/javascript-confirm/

`confirm()` lets us ask confirmation before performing something.

This API dates back to the dawn of the Web, and is supported by every browser.

It's very simple and I think it might come handy in many different cases without reaching for a custom-built UI.

Here's how it works: you call `confirm()`, passing a string that represents the thing we want to confirm, which is shown to the user:

```js
confirm("Are you sure you want to delete this element?")
```

This is how it looks in Chrome:

![Chrome browser confirm dialog showing "Are you sure you want to delete this element?" with Cancel and OK buttons](https://flaviocopes.com/images/javascript-confirm/chrome.png)

This is in Safari:

![Safari browser confirm dialog showing "Are you sure you want to delete this element?" with Cancel and OK buttons](https://flaviocopes.com/images/javascript-confirm/safari.png)

This is in Firefox:

![Safari browser confirm dialog showing "Are you sure you want to delete this element?" with Cancel and OK buttons](https://flaviocopes.com/images/javascript-confirm/safari.png)

As you can see it's rendered slightly differently in each browser, but the concept is the same.

> You should call `window.confirm()`, but since `window` is implicit, `confirm()` works

The browser blocks the script execution until the user clicks any of the OK or Cancel button. You can't escape from that without clicking a button.

The call to `confirm()` returns a boolean value that's either `true`, if the user clicks **OK**, or `false` if the user clicks **Cancel**, so we can assign it to a variable, or also use it in a conditional:

```js
const confirmed = confirm("Are you sure you want to delete this element?")
```

```js
if (confirm("Are you sure you want to delete this element?")) {
  console.log('confirmed')
}
```