[Home](./index.md) > [@firebase/auth](./auth.md) > [isSignInWithEmailLink](./auth.issigninwithemaillink.md) ## isSignInWithEmailLink() function Checks if an incoming link is a sign-in with email link suitable for [signInWithEmailLink()](./auth.signinwithemaillink.md). Signature: ```typescript export declare function isSignInWithEmailLink(auth: Auth, emailLink: string): boolean; ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | auth | [Auth](./auth.auth.md) | The Auth instance. | | emailLink | string | The link sent to the user's email address. | Returns: boolean