puppeteer/website/versioned_docs/version-19.3.0/api/puppeteer.page._eval.md
release-please[bot] c4803e4a37
chore: release main (#9313)
🤖 I have created a release *beep* *boop*
---


<details><summary>ng-schematics: 0.1.0</summary>

## 0.1.0 (2022-11-23)


### Features

* **ng-schematics:** Release @puppeteer/ng-schematics
([#9244](https://github.com/puppeteer/puppeteer/issues/9244))
([be33929](be33929770))
</details>

<details><summary>puppeteer: 19.3.0</summary>

##
[19.3.0](https://github.com/puppeteer/puppeteer/compare/puppeteer-v19.2.2...puppeteer-v19.3.0)
(2022-11-23)


### Miscellaneous Chores

* **puppeteer:** Synchronize puppeteer versions


### Dependencies

* The following workspace dependencies were updated
  * dependencies
    * puppeteer-core bumped from 19.2.2 to 19.3.0
</details>

<details><summary>puppeteer-core: 19.3.0</summary>

##
[19.3.0](https://github.com/puppeteer/puppeteer/compare/puppeteer-core-v19.2.2...puppeteer-core-v19.3.0)
(2022-11-23)


### Features

* **puppeteer-core:** Infer element type from complex selector
([#9253](https://github.com/puppeteer/puppeteer/issues/9253))
([bef1061](bef1061c06))
* **puppeteer-core:** update Chrome launcher flags
([#9239](https://github.com/puppeteer/puppeteer/issues/9239))
([ae87bfc](ae87bfc2b4))


### Bug Fixes

* remove boundary conditions for visibility
([#9249](https://github.com/puppeteer/puppeteer/issues/9249))
([e003513](e003513c0c))
</details>

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---
sidebar_label: Page.$eval
---
# Page.$eval() method
This method runs `document.querySelector` within the page and passes the result as the first argument to the `pageFunction`.
#### Signature:
```typescript
class Page {
$eval<
Selector extends string,
Params extends unknown[],
Func extends EvaluateFunc<
[ElementHandle<NodeFor<Selector>>, ...Params]
> = EvaluateFunc<[ElementHandle<NodeFor<Selector>>, ...Params]>
>(
selector: Selector,
pageFunction: Func | string,
...args: Params
): Promise<Awaited<ReturnType<Func>>>;
}
```
## Parameters
| Parameter | Type | Description |
| ------------ | -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------- |
| selector | Selector | the [selector](https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Selectors) to query for |
| pageFunction | Func \| string | the function to be evaluated in the page context. Will be passed the result of <code>document.querySelector(selector)</code> as its first argument. |
| args | Params | any additional arguments to pass through to <code>pageFunction</code>. |
**Returns:**
Promise&lt;Awaited&lt;ReturnType&lt;Func&gt;&gt;&gt;
The result of calling `pageFunction`. If it returns an element it is wrapped in an [ElementHandle](./puppeteer.elementhandle.md), else the raw value itself is returned.
## Remarks
If no element is found matching `selector`, the method will throw an error.
If `pageFunction` returns a promise `$eval` will wait for the promise to resolve and then return its value.
## Example 1
```ts
const searchValue = await page.$eval('#search', el => el.value);
const preloadHref = await page.$eval('link[rel=preload]', el => el.href);
const html = await page.$eval('.main-container', el => el.outerHTML);
```
If you are using TypeScript, you may have to provide an explicit type to the first argument of the `pageFunction`. By default it is typed as `Element`, but you may need to provide a more specific sub-type:
## Example 2
```ts
// if you don't provide HTMLInputElement here, TS will error
// as `value` is not on `Element`
const searchValue = await page.$eval(
'#search',
(el: HTMLInputElement) => el.value
);
```
The compiler should be able to infer the return type from the `pageFunction` you provide. If it is unable to, you can use the generic type to tell the compiler what return type you expect from `$eval`:
## Example 3
```ts
// The compiler can infer the return type in this case, but if it can't
// or if you want to be more explicit, provide it as the generic type.
const searchValue = await page.$eval<string>(
'#search',
(el: HTMLInputElement) => el.value
);
```