The present disclosure describes toilet flappers having an adjustable length cord. For example, the present disclosure describes a toilet flapper having a body and two arms. The body has a top surface and a bottom surface. On the top surface, there is a raised portion housing a cord, a locking mechanism, and a spring. In order to install the toilet flapper, a user can grab a hook attached to the end of the cord and pull enough of the cord out of the raised portion so that the user can attach the hook to, for example, a flush lever. Afterwards, the user can press down on the raised portion in order to activate the locking mechanism and prevent any more of the cord from being pulled back into the raised portion by the spring.