puppeteer/docs/api/puppeteer.page.evaluate.md
2023-07-17 10:52:54 +02:00

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---
sidebar_label: Page.evaluate
---
# Page.evaluate() method
Evaluates a function in the page's context and returns the result.
If the function passed to `page.evaluate` returns a Promise, the function will wait for the promise to resolve and return its value.
#### Signature:
```typescript
class Page {
evaluate<
Params extends unknown[],
Func extends EvaluateFunc<Params> = EvaluateFunc<Params>,
>(
pageFunction: Func | string,
...args: Params
): Promise<Awaited<ReturnType<Func>>>;
}
```
## Parameters
| Parameter | Type | Description |
| ------------ | -------------- | ------------------------------------------ |
| pageFunction | Func \| string | a function that is run within the page |
| args | Params | arguments to be passed to the pageFunction |
**Returns:**
Promise&lt;Awaited&lt;ReturnType&lt;Func&gt;&gt;&gt;
the return value of `pageFunction`.
## Example 1
```ts
const result = await frame.evaluate(() => {
return Promise.resolve(8 * 7);
});
console.log(result); // prints "56"
```
You can pass a string instead of a function (although functions are recommended as they are easier to debug and use with TypeScript):
## Example 2
```ts
const aHandle = await page.evaluate('1 + 2');
```
To get the best TypeScript experience, you should pass in as the generic the type of `pageFunction`:
```ts
const aHandle = await page.evaluate(() => 2);
```
## Example 3
[ElementHandle](./puppeteer.elementhandle.md) instances (including [JSHandle](./puppeteer.jshandle.md)s) can be passed as arguments to the `pageFunction`:
```ts
const bodyHandle = await page.$('body');
const html = await page.evaluate(body => body.innerHTML, bodyHandle);
await bodyHandle.dispose();
```