[Home](./index.md) > [@contract-case/case-definition-dsl](./case-definition-dsl.md) > [matchers](./case-definition-dsl.matchers.md) > [strings](./case-definition-dsl.matchers.strings.md) > [Base64Encoded](./case-definition-dsl.matchers.strings.base64encoded.md) ## matchers.strings.Base64Encoded class Transformation matcher that matches a base64 encoded version of the given string or string matcher WARNING: Since many strings are accidentally decodable as base64, this matcher is best combined with a more restrictive string matcher (eg `StringifiedJson`). **Signature:** ```typescript export declare class Base64Encoded extends AnyMatcher ``` **Extends:** AnyMatcher ## Constructors

Constructor	Modifiers	Description
[(constructor)(child)](./case-definition-dsl.matchers.strings.base64encoded._constructor_.md)		Transformation matcher that matches a base64 encoded version of the given string or string matcher WARNING: Since many strings are accidentally decodable as base64, this matcher is best combined with a more restrictive string matcher (eg `StringifiedJson`).

## Methods

Method	Modifiers	Description
[toJSON()](./case-definition-dsl.matchers.strings.base64encoded.tojson.md)		For non-TypeScript implementations (see `AnyMatcher.toJSON`)