Windshield crack repair depends on the damage’s size, depth, and location. Many chips and short cracks can be repaired with professional resin injection in about 30–90 minutes, while larger cracks, edge damage, and cracks affecting the driver’s primary viewing area often require windshield replacement.
Key Takeaways
- Many repairable windshield cracks up to about 6 inches can be repaired with professional resin injection, depending on their location and condition.
- Cracks in the driver’s primary viewing area are more likely to require replacement, including on vehicles equipped with Ford Co-Pilot360 or Hyundai SmartSense.
- DIY repair kits may produce poor results if air or contaminants remain in the damaged area.
- Edge cracks spread faster than many center chips and can turn a 3-inch repairable crack into a full replacement within days.
- Many comprehensive auto insurance policies cover windshield repair, although deductibles and coverage vary by insurer and policy.
Can You Fix A Cracked Windshield Yourself?
DIY windshield repair can work on a small chip, but trapped air or contamination can make the crack more difficult to repair professionally later. A windshield repair kit uses a repair applicator and UV-curing repair resin, while professional technicians use specialized vacuum-injection equipment to remove trapped air before injecting resin. DIY windshield repair kits are widely available, but long cracks generally require professional evaluation rather than a consumer repair kit.
DIY windshield repair also depends on the glass layer. Laminated safety glass has two layers with a plastic interlayer, so most windshield repairs are limited to damage affecting the outer glass layer. Clear packing tape can help reduce contamination before service. Consumer repair kits follow similar repair principles, but they do not eliminate the limitations of DIY windshield repair.
What Size Crack Can Be Repaired?
A chip smaller than a quarter, roughly 1 inch across, is the best repair candidate. A short crack under 6 inches can often be repaired.
Factors that determine whether a crack can be repaired
Repairability depends on more than crack length alone. Technicians typically evaluate:
- Crack length: Many cracks up to about 6 inches may be repairable.
- Damage depth: Repairs are generally limited to damage affecting the outer glass layer.
- Crack location: Damage in the driver’s primary viewing area is more likely to require replacement.
- Edge damage: Cracks reaching the windshield edge are more likely to spread.
- Contamination: Dirt and moisture inside the crack can reduce repair success.
The decision comes down to repair versus replacement. Damage in the driver’s primary viewing area is more likely to require replacement, even when the crack looks small. Edge cracks also push the decision toward replacement because they spread faster and threaten the windshield’s structural performance.
What Type Of Windshield Damage Can A Repair Kit Handle?
Bullseye and star damage are the most repairable chip patterns a consumer kit can handle.
DIY repair kits are most effective for
- Bullseye chips
- Star breaks
- Small combination breaks
- Minor damage limited to the outer glass layer
DIY repair kits are less effective for
- Long cracks
- Edge cracks
- Damage reaching the inner glass layer
- Cracks contaminated with dirt or moisture
Chip style matters more than appearance alone. A resin-based windshield repair kit can often fill bullseye and star-shaped impact damage when the damage remains within the outer glass layer of laminated safety glass. Long cracks and edge cracks generally require professional evaluation because consumer repair kits cannot restore the windshield’s structural strength.
How Does A Windshield Repair Kit Work?
A repair applicator helps remove trapped air before UV-curing repair resin is injected into the damaged area. A curing film holds the resin in place while ultraviolet (UV) light or sunlight hardens it. A razor blade removes excess cured resin, leaving the surface as smooth as possible.
Most DIY windshield repair kits follow the same basic process:
- Removing trapped air from the damaged area.
- Injecting repair resin into the chip or crack.
- Curing the resin with ultraviolet (UV) light.
- Removing excess cured resin to improve surface finish.
“Repair results depend on the damage’s size, depth, and location. Trapped air or contamination can reduce repair quality and may limit the success of professional resin injection.”
Modern Collision | I-CAR Gold Class Certified | 27 Years in Business
Repair decisions depend on the type, size, depth, and location of the damage. The table below summarizes common windshield damage types and the repair approach typically recommended for each.
| Damage Type | Typical Decision | Notes |
|---|---|---|
| Chip smaller than a quarter | Repair | Best repair candidate |
| Bullseye and star damage | Repair | Resin fills impact damage effectively |
| Long crack over 6 inches | Replace | Often exceeds common repair limits |
| Crack in the driver’s primary viewing area | Replace | Replacement is often recommended to maintain visibility |
| Professional resin injection | Repair pathway | Typically completed within about 30–90 minutes, depending on the damage |
How Do You Temporarily Slow A Windshield Crack?
Clear packing tape can help reduce contamination by keeping dirt and moisture out of the damaged area until professional repair. Super glue and clear nail polish are generally not recommended because they may interfere with professional resin repair.
Temporary Steps Before Professional Repair
Until the windshield can be inspected, you can help reduce further damage by:
- Applying clear packing tape over the damaged area.
- Keeping the windshield clean and dry.
- Avoiding automatic car washes.
- Avoiding sudden temperature changes whenever possible.
- Driving carefully on rough roads to reduce vibration.
Temperature fluctuations cause the glass to expand and contract, so the crack can still grow. Keeping the damaged area clean improves the chances of a successful repair by reducing contamination. Temporary measures buy time, but they do not restore the windshield’s structural strength or permanently stop a crack from spreading. If you need to protect the damage before professional repair, learn more about how to stop a windshield crack from spreading.
When Does A Cracked Windshield Need Replacement?
Windshield replacement becomes more likely when the damage exceeds common repair limits or affects safety-critical areas of the glass.
Damage Size
Larger cracks, deep breaks, and damage that extends beyond common repair limits are more likely to require windshield replacement. The exact repair limit varies depending on the windshield, the type of damage, and the repair technician’s assessment.
Damage Location
A crack in the driver’s primary viewing area is more likely to require windshield replacement because a repaired area may affect visibility. Edge cracks also deserve closer evaluation because they experience greater structural stress and may spread more quickly.
ADAS Considerations
Vehicles equipped with Advanced Driver Assistance Systems (ADAS) often require camera or sensor recalibration after windshield replacement. Proper calibration helps restore the accuracy of features such as:
- Lane departure warning
- Forward collision warning
- Automatic emergency braking
- Lane keeping assistance
Windshield & Glass Replacement restores the windshield to manufacturer specifications. Vehicles equipped with ADAS may also require calibration after installation to help ensure driver-assistance systems operate as intended.
How Does Professional Windshield Crack Repair Work?
Professional windshield crack repair uses resin injection and often takes about 30–90 minutes, depending on the damage. The repair process helps restore structural strength when the damage remains within repairable limits.
Professional technicians typically:
- Inspect the size, depth, and location of the damage.
- Use vacuum-injection equipment to remove trapped air from the crack.
- Inject repair resin into the damaged area.
- Cure the resin using ultraviolet (UV) light.
- Remove excess cured resin and finish the repair.
Vacuum injection helps reduce trapped air and improves resin penetration into the damaged area. Compared with most DIY repair kits, professional equipment generally produces a stronger and more consistent bond.
A small crack can often be repaired and returned to service the same day when the damage remains within repairable limits. However, some cracks cannot be repaired because of their size, depth, or location. If windshield replacement is recommended, learn more about how long windshield replacement takes to understand what to expect during the replacement process.
Does Insurance Cover Windshield Repair?
Comprehensive insurance coverage typically covers windshield repair and replacement. Insurance coverage may depend on
- Your insurance policy
- Whether comprehensive coverage is included
- Your deductible
- State insurance regulations
- Whether repair or replacement is recommended
Many insurers waive the deductible for windshield repairs because repairing the glass is usually less expensive than replacing it. Coverage, deductibles, and eligibility vary by insurer, policy, and state. Reviewing your insurance policy before scheduling service can help you understand your available coverage and any out-of-pocket costs, especially if you’re unsure whether your policy covers windshield replacement.
What Happens If You Do Not Fix A Cracked Windshield?
Temperature fluctuations, road vibration, and daily driving stress can turn a repairable chip into a larger crack. Dirt and moisture can also enter the damaged area, making later repair more difficult.
Delaying repair may:
- Allow the crack to spread beyond common repair limits.
- Reduce the likelihood of a successful resin repair.
- Increase the chance that windshield replacement becomes necessary.
- Affect driver visibility if the crack grows into the primary viewing area.
- Increase repair costs if the damage worsens.
A repairable crack may spread quickly depending on temperature changes, road conditions, and the location of the damage. Clear packing tape can help reduce contamination, but it cannot permanently stop a crack from spreading. Once the damage exceeds common repair limits, windshield replacement is often the safer option.
Get A Free Repair Vs. Replace Assessment
A professional inspection can determine whether a windshield crack is still repairable or whether Windshield & Glass Replacement is the safer option. A technician evaluates the crack’s size, location, depth, and level of contamination before recommending the appropriate solution. Early evaluation improves the chances of preserving a repairable windshield before the damage spreads further.
FAQs
Can you fix a cracked windshield yourself?
DIY windshield repair kits work best on small chips and minor damage. Incorrect application can reduce repair quality and may limit later professional repair options. Long cracks, edge damage, and cracks affecting the driver’s primary viewing area should be inspected by a qualified technician.
How big of a crack can be repaired?
Many repair facilities can repair cracks up to about 6 inches, depending on the crack’s location, depth, and overall condition. Damage in the driver’s primary viewing area is more likely to require replacement because repairs may affect visibility.
Does insurance cover windshield repair?
Comprehensive auto insurance typically covers windshield repair and replacement. Repairs usually cost less than replacements, so insurers may waive the deductible for repairs. Coverage, deductibles, and waiver eligibility vary by insurer and policy. Reviewing your insurance policy before scheduling service can help clarify your coverage.
What happens if you don't fix a cracked windshield?
Cracks may continue to spread because of temperature changes, road vibration, and everyday driving stress. A repairable crack may eventually require replacement if the damage extends beyond common repair limits. State laws vary, but windshield damage that obstructs the driver’s view may violate local vehicle safety regulations.
About the Author
Modern Collision is an I-CAR Gold Class Certified collision repair and auto glass shop serving drivers in Phenix City, Alabama. This content is based on industry repair practices and reviewed by experienced collision repair professionals.
Last updated: July 2026.