---
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 EvaluateFuncWith<NodeFor<Selector>, Params> = EvaluateFuncWith<
      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
);
```
