Wait for the `selector` to appear in page. If at the moment of calling the method the `selector` already exists, the method will return immediately. If the `selector` doesn't appear after the `timeout` milliseconds of waiting, the function will throw.
This method works across navigations:
```ts
const puppeteer = require('puppeteer');
(async () => {
const browser = await puppeteer.launch();
const page = await browser.newPage();
let currentURL;
page
.waitForSelector('img')
.then(() => console.log('First URL with image: ' + currentURL));
Promise which resolves when element specified by selector string is added to DOM. Resolves to `null` if waiting for hidden: `true` and selector is not found in DOM.
-`visible`: A boolean wait for element to be present in DOM and to be visible, i.e. to not have `display: none` or `visibility: hidden` CSS properties. Defaults to `false`.
-`hidden`: Wait for element to not be found in the DOM or to be hidden, i.e. have `display: none` or `visibility: hidden` CSS properties. Defaults to `false`.
-`timeout`: maximum time to wait for in milliseconds. Defaults to `30000` (30 seconds). Pass `0` to disable timeout. The default value can be changed by using the [Page.setDefaultTimeout()](./puppeteer.page.setdefaulttimeout.md) method.