puppeteer-extra-plugin-stealth/evasions/accept-language/readme.md

Stealth mode: Applies various techniques to make detection of headless puppeteer harder.

## API

<!-- Generated by documentation.js. Update this documentation by updating the source code. -->

#### Table of Contents

- [class: Plugin](#class-plugin)

### class: [Plugin](https://github.com/berstend/puppeteer-extra/blob/a769d9e78174808c217a71dc5a2261129b5b9127/packages/puppeteer-extra-plugin-stealth/evasions/accept-language/index.js#L37-L136)

- `opts` **[Object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)?** Options (optional, default `{}`)
  - `opts.locale` **[string](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)?** The locale to use in `Accept-Language` (default: `en-US,en;q=0.9`)
  - `opts.extraHeaders` **[Object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)?** Any other headers you would like to add to every request (default: `{}`)

**Extends: PuppeteerExtraPlugin**

By default puppeteer will not set a `accept-language` header in headless.

It's (theoretically) possible to fix that using either `page.setExtraHTTPHeaders` or a `--lang` launch arg.
Unfortunately `page.setExtraHTTPHeaders` will lowercase everything and launch args are not always available. :)

As a solution we hook into a deeper level and add the header there in case it's missing (capitalized correctly).
A challenge poses the restriction that only a single request listener can modify the request, so we need to take care of that.

It's possible to override the default locale or add additional headers.

Example:

```javascript
const puppeteer = require('puppeteer-extra')

const StealthPlugin = require('puppeteer-extra-plugin-stealth')
const stealth = StealthPlugin()
stealth.enabledEvasions.delete('accept-language') // Remove a specific stealth plugin from the default set
puppeteer.use(stealth)

const AcceptLanguagePlugin = require('puppeteer-extra-plugin-stealth/evasions/accept-language')
const acceptLanguage = AcceptLanguagePlugin({ locale: 'de-DE,de;q=0.9' }) // Custom locale
puppeteer.use(acceptLanguage)
```

---