What Is a Star Break in a Windshield?
Reviewed by the Skyview Auto Glass technical team — NWRD-, ASE- and DINITROL-trained technicians · Updated November 2026
Quick answer
A star break is a chip with short legs radiating outward from a central impact point, like a small asterisk. It forms when a stone hits at an angle that sends cracks outward instead of punching a clean cone. The legs can stay short or run across the glass over time.
How a star break forms
A star break starts when a stone strikes the windshield at an angle or with a glancing force. Instead of carving a round cone, the impact sends several short cracks outward from the point of impact, giving the break its star or asterisk shape. The center is a small pit, and the legs fan out from it.
The legs are the concern. A fresh star with short legs repairs well, but each leg is a crack that can lengthen under temperature swings, body flex, or a door slam. The longer the legs grow, the less likely a repair is and the closer the windshield is to needing replacement.
Star breaks often sit in the outer glass layer, but a hard impact can drive a leg through to the inner layer, which usually means replacement rather than repair. That is why a technician assesses the legs before deciding whether a resin fill will hold.
When a star break is heading toward replacement
- The legs stay short and contained
- A repair can bond the break and stop the legs from running.
- One or more legs have lengthened past half an inch
- The break is growing, and repair becomes less reliable.
- A leg reaches the edge of the glass
- Edge-reaching cracks usually mean a replacement.
What to do right after a star break
- Cover the impact point with clear tape to keep dirt and water out.
- Note the date you noticed it, since legs can grow fast.
- Close doors gently and stay off rough pavement.
- Get the repair booked within a couple of days while the break is fresh.
- Skip the car wash until the repair is done.
Repair it before the legs run
A star break with short legs bonds cleanly because the resin can flow into each leg. Once the legs lengthen, the fill becomes less reliable and replacement more likely. Repairing early, while the legs are short, gives the best result.
More questions about star breaks
Can a star crack be repaired?
Yes, when the legs are short. A star break with legs under about six inches total can often be repaired. Long legs or legs reaching the edge usually mean replacement.
What is a star break in a windshield?
It is a chip with short cracks radiating from a central impact point. The legs can stay short or run across the glass over time.
Will a star break spread?
It can. Each leg is a crack that may lengthen from temperature swings or vibration. Repairing it early bonds the legs and stops the growth.
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