[Home](./index.md) > [@firebase/auth-types](./auth-types.md) > [PhoneAuthCredential](./auth-types.phoneauthcredential.md) > [fromJSON](./auth-types.phoneauthcredential.fromjson.md) ## PhoneAuthCredential.fromJSON() method Static method to deserialize a JSON representation of an object into an [AuthCredential](./auth-types.authcredential.md). Signature: ```typescript static fromJSON(json: object | string): PhoneAuthCredential | null; ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | json | object \| string | Either object or the stringified representation of the object. When string is provided, JSON.parse would be called first. | Returns: [PhoneAuthCredential](./auth-types.phoneauthcredential.md) \| null If the JSON input does not represent an [AuthCredential](./auth-types.authcredential.md), null is returned.