<!-- Do not edit this file. It is automatically generated by API Documenter. --> [Home](./index.md) > [puppeteer](./puppeteer.md) > [LaunchOptions](./puppeteer.launchoptions.md) > [extraPrefsFirefox](./puppeteer.launchoptions.extraprefsfirefox.md) ## LaunchOptions.extraPrefsFirefox property [Additional preferences](https://searchfox.org/mozilla-release/source/modules/libpref/init/all.js) that can be passed when launching with Firefox. <b>Signature:</b> ```typescript extraPrefsFirefox?: Record<string, unknown>; ```