Air carrier flight crew reported a cracked cockpit windshield during initial climb. Returned to departure airport uneventfully.

Narrative

Departed ZZZ Runway XXR/Intersection 1. Departure instructed to fly direct to ZZZZZ; climb to FL230; and 300 kts. or greater thru 10;000 ft. Climbing thru 8000 or 9000 I noticed my window; R1 had a circle of light on the upper edge; eraser head size. I mentioned; is that the sun reflecting from behind the aircraft or is that an arc? We concluded it was arcing. The arcing stopped and then not immediately but shortly after ; the window cracked from top to bottom and across. The Captain had me request a level off and vectors to run the checklist. After I completed the Window Damage-Forward checklist (cracked or shattered) the Captain transferred controls to me and he contacted Maintenance and Dispatch. We initially leveled off at 15;000 and then stepped down a few thousand feet more for traffic during a box pattern of vectors in the vicinity of the ZZZ VOR. The Captain returned from the other radio and discussed his thoughts with me and he ultimately decided the best course would be to return to ZZZ with an overweight landing. We [requested priority handling] with ATC for added safety considerations. We landed on Runway XXL and taxied to Gate XX.