EMB 170 First Officer reported the Captain's windshield cracked during cruise climb. Flight crew descended and completed a safe diversion.

Narrative

After taking off from ZZZ1 with a destination of ZZZ2; we were climbing through FL270. I heard a bang that sounded similar to a drink cart banging into the wall. I looked up and saw that the captain's side of the windshield had spiderwebed. We began the QRH procedure and decided to divert to ZZZ.We alerted ATC and the flight attendants and began descending. We then decided to [request priority handling] with ATC.The captain was flying but gave me the controls since he had little visibility on his side and as part of the QRH. The captain notified the flight attendants with more detailed information and the passengers.The captain noticed damage increasing as the flight continued. However it never seemed to breach the inner layer of the windshield and we had no issues with pressurization.We configured the plane for landing at ZZZ and were able to land without incident. The visibility on the ground was sufficient for the captain to carefully taxi to a gate. The remainder of the time on the ground was uneventful including deplaning the passengers at the gate.I'm not sure if a maintenance inspection might have caught anything wrong with the windshield but that's the only thing I can think of that may have caught a problem with the windshield.