Yes. Xanax (alprazolam) and Klonopin (clonazepam) are both benzodiazepines.
They have essentially identical side effects and are used for an essentially identical list of conditions. The duration of action for clonazepam is longer. These drugs should not be used at the same time, but may be used by the same patient at different times of day (for example Xanax during the day as needed and Buy Klonopin Online 1mg at bedtime).
As prescription drugs and controlled substances, each should only be used (together or in combination) as prescribed.