A chip is a small impact mark where glass has broken away, but it matters more than it looks
A chip is a small piece of glass that has broken out of your windshield, usually from a rock or debris hit while driving. The damage stays in one spot and does not spread across the glass like a crack does. A chip can be the size of a pinhead or as large as a quarter—the size determines whether it affects your safety and whether repair is possible.
The danger of a chip depends on three things: where it is on the glass, how deep it goes, and whether it is growing. A chip in your line of sight (the area directly in front of the driver) is a visibility problem. A chip that has gone all the way through the glass weakens the structural integrity of the windshield. A chip that is spreading into a crack means the damage is getting worse and repair becomes impossible.
Most chips can be repaired if you catch them early. The repair fills the damaged area with a clear resin that hardens and restores the strength of the glass. If a chip is ignored and turns into a crack, or if it is already too large, replacement is the only option.
Key Takeaways
- A chip smaller than a quarter and not in your direct line of sight can usually be repaired rather than replaced.
- Chips in the driver's sight line are a safety issue and should be addressed before the next long drive.
- A chip that has spread into a crack or gone completely through the glass cannot be repaired and requires replacement.
- Repair costs less than replacement and takes one to two hours, while replacement takes several hours and requires curing time.
- Driving with a chip does not when ready cause failure, but temperature changes and road vibration can make it spread.
How a chip forms and why it spreads
Windshield glass is made of two layers of glass bonded to a plastic interlayer. When a rock or road debris hits the glass at speed, it breaks the outer layer and sometimes penetrates into the interlayer. The impact creates a small crater of broken glass—that is the chip.
A chip stays small if the glass around it is stable. But temperature swings, road vibration, and pressure changes inside the car can cause the glass to flex. Each flex puts stress on the edges of the chip. Over weeks or months, that stress can cause the chip to spread into a crack that branches across the windshield. Once a crack starts, it grows faster and repair becomes impossible.
Chips in the center of the windshield are less likely to spread than chips near the edges, because the center is under less stress. Chips near the frame or in corners are under constant flexing pressure and are more likely to become cracks.
When a chip can be repaired
A chip can be repaired if it meets three conditions: it is smaller than a quarter (about one inch across), it has not spread into a crack, and it is not in the critical sight line directly in front of the driver's eyes. Some repair shops will repair chips slightly larger than a quarter if the damage is shallow, but most will not may provide the repair if the chip is bigger.
The repair process takes one to two hours. A technician cleans out the damaged area, injects clear resin into the chip under pressure, and allows it to cure. The resin hardens to the same hardness as glass and bonds the broken pieces back together. The repair restores the structural strength of the windshield and makes the chip nearly invisible.
Repair is much cheaper than replacement—typically one-third to one-half the cost of a new windshield. Many insurance policies cover glass repair with little or no deductible, even if they do not cover replacement. Check your policy to see whether repair is covered before you pay out of pocket.
When replacement is necessary
A chip must be replaced rather than repaired if it is larger than a quarter, if it has spread into a crack, if it has gone completely through both layers of glass, or if it is in the critical sight line and cannot be polished smooth. A chip in the driver's direct line of sight is a safety issue because it distorts vision and can cause glare or reflections that interfere with seeing the road.
Replacement takes four to six hours from start to finish, but the windshield cannot be driven on for at least one hour after installation while the adhesive cures. Many shops recommend waiting 24 hours before driving at highway speeds. The new windshield is bonded to the frame with a strong polyurethane adhesive that holds the glass in place and contributes to the structural rigidity of the car body.
Replacement costs vary widely depending on the make and model of your car, the type of glass (standard or heated), and whether the windshield has a rain sensor or heads-up display. Luxury vehicles and those with advanced sensors cost significantly more to replace than basic models.
The difference between a chip and a crack
A crack is a line that spreads across the glass, while a chip is a localized break in one spot. A crack can start from a chip if the chip is not repaired and stress causes it to spread. A crack can also start from a chip impact that is severe enough to fracture the glass in a line rather than just breaking out a piece.
Cracks cannot be repaired—they can only be replaced. A crack that is spreading is also a safety issue because it weakens the structural integrity of the windshield. In a collision, a windshield with a crack may not hold the glass in place or support the roof structure the way a sound windshield does.
The distinction matters because repair is an option for chips but not for cracks. If you see a chip, get it repaired before it has a chance to spread into a crack.
What to do if you get a chip
Stop driving in extreme temperatures as soon as you notice a chip. Rapid temperature changes—such as blasting the defroster on a cold morning or parking in the sun after driving in shade—put stress on the glass and can cause a chip to spread. If you must drive, keep the temperature inside the car moderate and avoid sudden changes.
Contact a glass repair shop within a few days of the chip appearing. Many shops can fit you in the same day or next day. Bring your insurance card if you have glass coverage, because the shop can often bill the insurance directly and you may owe nothing out of pocket.
If the chip is small and not in your sight line, you can usually drive normally while waiting for the appointment. If the chip is large, in your sight line, or spreading, avoid highway driving and do not drive at night until it is repaired or replaced. A large chip or crack in your sight line is a visibility hazard and can be grounds for a traffic stop in some states.
How insurance covers glass damage
Most comprehensive auto insurance policies cover glass damage including chips and cracks. Coverage usually applies to repair and replacement with little or no deductible—often $0, $100, or $250 depending on your policy. Some insurers offer glass coverage with no deductible at all.
Check your policy documents or call your insurer to find out what your glass deductible is and whether repair and replacement are both covered. If you have not looked at your policy in years, you may be surprised to find that glass coverage is better than you thought. Many people pay out of pocket for repairs that their insurance would have covered.
If you do not have comprehensive coverage, repair costs are your responsibility. Repair shops often offer discounts for cash payment or can work with you on payment plans.
Frequently Asked Questions
Can I drive with a chip in my windshield?
Yes, a small chip away from your sight line is safe to drive on. But avoid extreme temperature changes and rough roads, because vibration and temperature stress can cause the chip to spread into a crack. If the chip is in your direct line of sight or is larger than a quarter, avoid highway driving and get it repaired or replaced soon.
Will a chip turn into a crack?
A chip can spread into a crack if it is stressed by temperature changes, road vibration, or pressure. Chips near the edge of the windshield are more likely to spread than chips in the center. Repairing a chip early stops it from spreading and is much cheaper than replacing the whole windshield later.
How much does windshield chip repair cost?
Repair typically costs between $50 and $150 depending on the size and location of the chip and the shop you choose. Many insurance policies cover repair with no deductible or a small one, so check your policy before paying out of pocket. Replacement costs much more—usually $300 to $1,000 or more depending on your vehicle.
Can I repair a chip myself?
DIY chip repair kits are sold at auto parts stores and online, but they do not work as well as professional repair. The resin in a kit does not cure under the same pressure as shop equipment, and the repair may not be as strong or as clear. Professional repair is worth the cost because it restores the full strength of the glass and is nearly invisible.
What if my chip is spreading?
If you see a line starting to spread from the chip, stop driving in temperature extremes and contact a glass shop when ready. A spreading chip will soon become a crack that cannot be repaired. If the spread has already become a visible crack, replacement is your only option.