For the heck of it
Definition 1 of 1
Pro Tip 1/3Casual Language
Used mainly in informal contexts among friends or in casual conversation. 
I tried sushi for the heck of it at the party last night.
Pro Tip 2/3Spontaneity
Reflects acting on a whim or without planning, often to indicate a sudden decision. 
They took a road trip for the heck of it.
Pro Tip 3/3Playful Tone
Conveys a light-hearted or playful attitude, and shouldn't be taken too seriously. 
He started singing loudly for the heck of it.