[Home](./index.md) > [puppeteer](./puppeteer.md) > [CustomQueryHandler](./puppeteer.customqueryhandler.md) ## CustomQueryHandler interface Contains two functions `queryOne` and `queryAll` that can be [registered](./puppeteer.puppeteer.__experimental_registercustomqueryhandler.md) as alternative querying strategies. The functions `queryOne` and `queryAll` are executed in the page context. `queryOne` should take an `Element` and a selector string as argument and return a single `Element` or `null` if no element is found. `queryAll` takes the same arguments but should instead return a `NodeListOf` or `Array` with all the elements that match the given query selector. Signature: ```typescript export interface CustomQueryHandler ``` ## Properties | Property | Type | Description | | --- | --- | --- | | [queryAll](./puppeteer.customqueryhandler.queryall.md) | (element: Element \| Document, selector: string) => Element\[\] \| NodeListOf<Element> | | | [queryOne](./puppeteer.customqueryhandler.queryone.md) | (element: Element \| Document, selector: string) => Element \| null | |