Written By: Don Dodi
Fact Checked By: Kristen Brown
Reviewed By: Diego Rosenberg
Now small crack on the windshield can become the serious security risk in future, which is why you need to fix it as they are right now.
And even a tiny crack can actually quickly spread due to the temperature changes, road vibrations or additional impact as well, which puts both the driver and passengers at risk.
As well as, the studies shows that the cracks which is longer than 6 inches significantly more likely to fail in crash scenarios or under stress as well.
Plus, NHTSA shows that the windshield actually plays a crucial role as it maintain the structural integrity of a vehicle, specially during the front-end collisions and rollovers.
Additionally, many minor windshield cracks can be easily repaired at home by using affordable repair kits.
So, this is the guide which shows you How To Repair a Cracked Windshield and it is really easy method.
Common Causes of Windshield Cracks
Each cause is presented under its clear heading in simple language with useful explanations and factual knowledge.
1. Road Debris (Like Rocks and Gravel)
The most common reason for a windshield to break is because small objects hit the glass while driving.
These are often small stones or gravel kicked up by the tires of vehicles ahead of you, specially trucks. When these hard particles hit the windshield at high speeds, chips or cracks can form immediately.
According to the Auto Glass Safety Council, more than 80% of windshield damage is caused by road debris. Cracks often start as small shards but can grow quickly if not repaired promptly.
Keeping a safe distance from other vehicles, specially on highways or gravel roads, is one of the best ways to avoid this type of damage.
2. Temperature Extremes (Also Known as Thermal Shock)
Glass expands in the heat and contracts in the cold. If your windshield experiences a sudden change in temperature, it can crack due to thermal stress.
For example, pouring hot water on a frozen windshield or turning on a very hot defroster on a cold morning can cause the glass to expand too quickly and crack. Similarly, direct sunlight can cause a small crack to heat up and become a long crack.
Studies show that temperature-related cracks often occur in the morning or evening when temperatures change rapidly. To avoid this, always try to warm or cool your windshield gradually and avoid sudden changes in temperature.
3. Poor Installation or Structural Stress
If the windshield isn’t installed properly, it may not fit snugly in its frame. This imbalance causes uneven pressure on the glass, increasing the risk of cracking—even with normal driving or slight body tilting.
This type of stress crack often appears on the edges of the windshield and can occur even without any impact. Research conducted by automotive safety experts shows that improper installation can reduce the strength of a windshield by up to 60%.
Always have your windshield installed by certified technicians using manufacturer-approved adhesives and techniques to ensure long-term protection.
4. Previous Repairs or Aging Glass
Older windshields, or those that have been repaired, are more likely to break again. Over time, sunlight, weather and vibration can weaken the structural strength of the glass.
Even a well-performed repair won’t last long if the surrounding glass continues to get damaged. According to insurance industry statistics, windshields older than 5 years are 30-50% more likely to develop new cracks.
Inspecting your windshield regularly and replacing it if it’s excessively worn, is an important step in maintaining road safety.
Types of Windshield Cracks
Each type of crack is explained under its heading in factual and simple language to help readers identify and understand the nature of the damage to their windshield. This will help them decide if repair is possible or if replacement is necessary.
1. Chip (Smaller Than a Dime)
Windshield cracking is one of the most common types of damage. It is usually caused by a small object such as a stone hitting the glass and creating a small dent or pit.
Chips are usually smaller than the size of a penny (about 1 cm) and may appear circular or slightly oval. Although they may seem harmless, small chips can turn into larger cracks due to vibration, weather or pressure.
According to the National Windshield Repair Association (NWRA), chips smaller than 1 inch can often be repaired with resin before they become worse.
2. Star Break
Star fission looks like a star explosion – a central impact point with cracks spreading outward like the spokes of a wheel.
These cracks can spread quickly, specially if exposed to heat, cold or car movement. These cracks are often caused by sharp impacts such as flying gravel or metal debris.
If the star breaks are smaller than 3 inches, they can be repaired, but larger ones or those visible to the driver may need to be replaced entirely. Regular inspection is important, as such cracks can grow suddenly and without warning.
3. Bullseye
A bullseye crack is named because of its shape – it resembles a circular target with a deep impact point in the center and concentric rings surrounding it.
This is usually caused by blunt, round objects such as stones or baseballs. These cracks are deeper and more obvious than chips or star breaks. If detected early, bullseye cracks smaller than a quarter (about 2.5 cm) can be repaired effectively.
However, if the rings begin to expand or change color, this is a sign that the damage may have compromised the structural strength of the windshield.
4. Combination Break
As the name suggests, combination breaks are a mix of several types of cracks—often a chip or bullseye-like crack with star-like cracks radiating from it. These are more difficult to repair because they affect the glass in multiple ways.
Joint damage is often caused by high-speed blows or multiple blows to the same area. Many experts recommend early evaluation of this type of damage because the risk of it spreading is high.
If the damage is within the size range and not near the edges then repair may still be possible.
5. Long Crack
A long crack is any crack longer than 6 inches (15 cm). These cracks usually start from a small chip or stress point and slowly spread across the windshield due to pressure, vibration, or changes in temperature.
Long cracks often extend in a straight line and can cross the driver’s field of vision. Unfortunately, in most cases, long cracks are not repairable.
The Auto Glass Safety Council recommends replacing a windshield for any crack longer than a dollar bill, as this compromises the integrity of the glass.
6. Edge Crack
Edge cracks can start as little as 2 inches from the windshield’s edge and spread quickly. These cracks are often caused by pressure exerted on the glass’s weakest structural point, its outer perimeter.
Poor installation, body flexing, or previous damage near the edges are common causes. Cracks along the edges are particularly dangerous because they can reduce the strength of the windshield and increase the risk of it shattering during an accident.
According to safety experts, more than 70% of broken windshields that require replacement have cracks on the edges.
When to Repair vs. Replace a Cracked Windshield
This section helps readers understand the key factors that determine whether a windshield crack can be repaired or needs to be replaced completely. Each factor is explained under clear headings with simple language and factual knowledge.
1. Size and Depth of the Crack
The first thing to consider is the size and depth of the damage. Most small chips (smaller than a dime coin) and short cracks (less than 6 inches long) can usually be repaired.
However, if the crack is longer than a dollar bill (about 6 inches) or the chip is deep enough to penetrate more than one layer of glass, replacement is usually the safest option.
According to the Auto Glass Safety Council, cracks deeper than the outer glass layer often weaken the structural integrity of the windshield, making it unsafe to drive.
2. Location of the Crack
Where the crack is located also makes a big difference. If the crack is directly in the driver’s line of sight, even a minor repair could cause distortions or blurring that can reduce visibility.
For safety reasons, professionals often recommend windshield replacement in such cases. Similarly, cracks near the edges of a windshield—usually within 2 inches—can spread quickly due to stress and vibration.
These edge cracks are more likely to weaken the windshield’s ability to absorb impact, making replacement a better option.
3. Number of Cracks
The number of cracks on your windshield also matters. If your windshield only has one or two small cracks or chips, repairs are usually possible and affordable.
But if your windshield has multiple cracks or damaged areas, even if each is small, it may be too weak to safely repair.
The more cracks there are, the more likely they are to join or expand, specially during fast driving, temperature changes or stress. In such cases, complete glass replacement is often recommended to restore its strength and clarity.
4. Local Regulations and Safety Laws
Some states or countries have legal guidelines that determine whether a windshield can be repaired or must be replaced.
For example, several US states prohibit repairs if the crack is in the driver’s view or the damage affects built-in technology such as lane sensors or rain-detection systems.
If your windshield does not meet visibility or safety standards, law enforcement officers may issue fines. Always check with your local DMV or road safety authority for rules in your area.
Even if repair is possible, replacement may be required for safety and compliance under the law.
Tools
| Tool / Material | What It Is | What It’s Used For | Extra Tips |
|---|---|---|---|
| Windshield Repair Kit | Ready-to-use kit that includes resin (liquid glue), an applicator (syringe) and curing strips (transparent film). | Used to fill the crack or chip with special resin that hardens and seals the glass. | Choose a kit containing UV resin for better durability. |
| Razor Blade | A small, sharp flat blade, as used in box cutters or paint scrapers. | It is used to remove excess resin after drying and to make the surface smooth. | Always handle with care – store safely after use. |
| Glass Cleaner | A liquid spray specially made for cleaning car windows. | It is used to clean the windshield before beginning a repair to ensure the resin sticks properly. | Avoid ammonia-based cleaners—they can affect resin bonding. |
| Microfiber Cloth | A soft, lint-free cloth made from fine fibers. | Used to dry and wipe glass without scratching it. | Wash before use to remove any loose fibers. |
| UV Light (Optional) | A small portable lamp that emits ultraviolet (UV) rays. | Speeds up the resin’s hardening process, specially on cloudy days or indoors. | If you don’t have it, sunlight will still work – it just will take longer. |
Safety Precautions Before You Start a Windshield Repair
These safety steps are essential to ensure that the repair process is effective and does not cause further damage. Each point is organised under a clear heading with a detailed explanation using simple, useful language and real facts.
1. Park in a Shaded, Dry Area
Before you begin windshield repair, always park your car in a shady and dry place—like a carport, garage, or under a large tree. This helps in several ways:
- Direct sunlight can cause the resin to dry too quickly before it has fully expanded into the crack or piece, leading to an uneven repair.
- Moisture (such as rain, dew or humidity) can get into the crack and prevent the resin from properly bonding to the glass.
- Additionally, the heat of direct sunlight can cause the crack to enlarge before repairs can even begin.
Auto repair experts recommend working in temperatures between 15°C to 27°C (60°F to 80°F) for best results.
2. Ensure the Windshield is Clean and Dry
Make sure the area around the crack is completely clean and dry before applying any repair materials. Use glass cleaner and a microfiber cloth to wipe away dust, dirt, grease and water.
If there is even a small amount of water or debris in the crack, it can trap air bubbles in the resin or prevent the damage from healing completely.
According to auto glass technicians, 80% of failed repairs are due to poor surface preparation. So take your time completing this step—it really matters.
3. Wear Protective Gloves and Safety Glasses
Although repairs are easy, it’s still important to protect yourself. Always wear:
- Wear protective gloves to avoid getting resin on your hands, as it can cause skin irritation or allergic reactions.
- Wear safety glasses to protect your eyes in case resin accidentally splashes or the razor blade slips.
Windshield resin is a chemical compound and although it’s safe when used as directed, it can be harmful if made into direct contact. Additionally, the edges of broken glass—even small pieces—can be sharp.
How To Repair a Cracked Windshield – Best Method
This section provides a complete description of each step of the windshield repair process, with simple language and practical explanations, so readers know what to do and why it’s important.
1. Clean the Windshield and Crack Area
Before you begin repairs, it’s important to clean the glass thoroughly. Use a high-quality glass cleaner and a microfiber cloth to remove dust, dirt and grease from the windshield—specially around the crack or chip.
Small particles or moisture trapped in the damaged surface can also prevent the resin from adhering properly. According to professional auto glass technicians, over 70% of failed DIY repairs are caused by poor surface cleaning.
Make sure the glass is completely dry before moving on to the next step.
2. Apply the Resin Using the Injector
Next, open your windshield repair kit and set up the resin applicator (usually a syringe or plunger-style tool).
Place it directly over the crack or chip. Slowly pour the liquid resin into the damaged area. This resin is specially formulated to fill cracks and restore the strength and beauty of glass.
The pressure of the injector helps the resin penetrate deep into even the smallest cracks and air pockets. Be patient with this step—it may take a few minutes for the resin to fully set in the crack.
3. Use Curing Strips to Seal the Resin
Once the resin has filled the crack, apply a curing strip (which is usually included in the kit) directly to the repair area. These strips are made of a transparent plastic film that helps keep the resin flat and in place until it hardens.
Press it down gently to ensure there are no bubbles underneath. The curing strip also protects the repair site from dust or air that can affect the bonding process. This step is essential for a smooth, clean finish.
4. Let It Cure Under Sunlight or UV Lamp
The resin needs to harden or “cure” to become strong and invisible. You can do this by placing the car in direct sunlight for 15 to 45 minutes, depending on the brand of resin used and the weather conditions.
If you are working indoors or on a cloudy day, you can also use a UV light (ultraviolet lamp), which will help the resin set faster. Setting causes the resin to adhere to the glass, sealing the crack completely and preventing it from spreading further.
5. Remove Excess Resin with a Razor Blade
When the resin has completely set and is hard to the touch, gently peel off the curing strip. Then, take a razor blade and scrape off the excess resin from the surface. Keep the blade perpendicular to the glass to avoid scratching the glass.
This step helps to level the surface and remove any sticky residue left behind. It also improves visibility and makes the repaired area blend in with the rest of the windshield.
6. Polish the Area for a Clean Finish
Finally, polish the repaired area with a soft microfiber cloth and a little glass polish (optional). This smooths the surface and improves clarity.
A well-polished repair will be nearly invisible, specially from a distance. It also prevents dirt or moisture from accumulating in the area in the future.
While it may not look “brand new,” proper DIY repairs can restore up to 90-95% of a windshield’s original strength, according to a study by the Auto Glass Safety Council.
When to Seek Professional Help for Windshield Cracks
While many minor cracks and chips can be repaired at home, not all windshield damage is safe or suitable for do-it-yourself repair.
Some situations require skills, tools and materials that only a trained auto glass professional can provide. Below are some key signs that you should seek professional help to avoid safety risks and costly mistakes.
1. Cracks Longer Than 6 Inches
If your windshield has a crack longer than 6 inches (about the length of a dollar bill), it usually cannot be safely repaired.
Longer cracks weaken the structural integrity of the glass and are more likely to spread over time, specially when exposed to heat, shocks, or vibrations.
According to the Auto Glass Safety Council, cracks larger than 6 inches are a major safety concern and should be repaired by a professional who may replace the entire windshield.
Attempting to repair long cracks at home often reduces visibility and increases the risk of failure in the event of an accident.
2. Cracks Near Windshield Edges
Cracks or chips within 2 inches of the windshield’s edge are particularly dangerous. The edges of the windshield are under the most stress and play a vital role in holding the glass to the car’s frame.
Damage in this area spreads rapidly and increases the likelihood of the windshield being ejected during a collision or airbag deployment.
Professionals use special adhesives and installation techniques to keep the edge sealed and strong. If the crack is near the edge, replacement is often the only safe solution.
3. Damage in the Driver’s Direct Line of Vision
If the crack or chip is right in front of the driver’s field of view, it’s best to consult a professional. Even minor repairs in this area can leave slight distortions or visual defects that can interfere with safe driving—specially in low light or rainy conditions.
Many states have laws prohibiting windshield repairs in the driver’s line of sight because of visibility hazards. A professional technician can assess whether the repair is legal and visually acceptable—or whether replacement is the safe and legal option.
4. Complex Cracks (e.g., Multiple Intersecting Cracks)
If your windshield has multiple cracks, star breaks, or combined damage with cracks extending in different directions, it is considered complex damage. These types of cracks often affect a large portion of the windshield and cannot be completely sealed with a DIY kit.
Even though the crack may seem minor, the inner layers of the glass may already be damaged. Professional repair services use equipment such as vacuum injectors, high-grade resins and curing lamps to repair the glass more effectively compared to home kits.
In most cases, replacement is the only long-term solution for complex or spreading cracks.
Cost of Windshield Repair vs. Replacement
Understanding the cost differences between windshield repair and replacement helps you make a smart, budget-friendly decision.
Whether you’re fixing a small chip or dealing with a long crack, this description shows you what to expect in terms of pricing and how insurance can reduce the cost.
1. Average Cost of DIY Repair Kits ($10–$30)
If the crack or chip is small and easy to reach, you can fix it yourself with a DIY windshield repair kit. These kits typically cost between $10 and $30 and they include everything you need: resin, applicator, curing strips and easy instructions.
These are best suited for small chips and cracks less than 6 inches in length. According to Consumer Reports, many high-quality kits can restore up to 90% of the glass’s strength and clarity when used correctly.
This is the most economical option, specially for small repairs that are done quickly.
2. Professional Repair Cost Range ($50–$150)
If you don’t feel confident doing it yourself or the crack is a little more complicated, professional windshield repair is a good option.
Most repair shops charge between $50 and $150 depending on the size, type and location of the damage. This includes the technician’s expertise, professional resin and often a warranty for peace of mind.
If the damage is repairable and not in the driver’s line of sight, this is a safe, effective and still relatively low-cost option.
3. Full Windshield Replacement Costs ($200–$1,000+)
When the crack is very long, near the edge, in the driver’s view, or is part of a complex crack, the entire windshield usually needs to be replaced.
It can cost anywhere from $200 to $1,000, depending on the make, model and technical specifications of your car.
Vehicles that have built-in sensors, lane assist cameras, rain detection cameras, or heating elements may cost more to replace because re-calibration is often necessary after installation. For example:
- Standard Sedan: $200–$400
- SUV/Truck: $300–$700
- Luxury cars or ADAS-equipped models: $800–$1,200+
4. Insurance Coverage Considerations
Many car insurance policies — specially comprehensive coverage plans — include windshield repair or replacement.
In some states, such as Florida, Kentucky and South Carolina, insurance companies are required to waive the deductible for windshield repair or replacement.
This means you won’t have to pay anything out of your pocket. However, if you file a claim in other states, you may have to pay a deductible amount (usually $100-$500).
It’s a good idea to check with your insurance provider before proceeding, as some may even recommend preferred glass repair shops or send a mobile technician to your location.
Preventing Future Windshield Cracks
Fixing a cracked windshield is important—but preventing it from happening again can save you time, money and stress.
Windshields are exposed to many hazards daily, but by following a few simple habits, you can greatly reduce the risk of cracks or chips. Here’s how to keep your windshield strong and clear for the long haul.
1. Maintain a Safe Following Distance Behind Other Vehicles
One of the most common causes of windshield damage is road debris—small stones, gravel, or other objects kicked up by the tires of vehicles in front of you, specially trucks. These can hit your windshield at high speeds and cause instant chips or cracks.
By maintaining a safe distance of at least 3-4 seconds, you give yourself more time to react and reduce the risk of impact.
The Auto Glass Safety Council recommends staying even further back when driving on gravel roads, construction zones or highways where flying debris is more likely.
2. Avoid Sudden Temperature Changes
Windshields are made of laminated glass, which can expand or contract with temperature. If the glass’s temperature changes too quickly—such as pouring hot water on a frozen windshield or running the heater at full power in cold weather—this can cause thermal stress cracks.
They usually start small and then spread rapidly. To avoid this, warm or cool your windshield gradually. Use the defroster on low or medium temperature and never apply direct heat or boiling water to ice-covered glass.
3. Park in Shaded or Covered Areas When Possible
Whenever possible, park your car in a garage, under a carport, or in a shady spot. This will protect your windshield from direct sunlight, which can heat the glass unevenly and make existing chips worse.
Prolonged exposure to UV rays can weaken the protective seal and cause small cracks to develop over time. In hot weather, the temperature difference between the inside and outside of the windshield can be more than 40°F (4°C), increasing the risk of cracking.
Covered parking also provides protection from falling debris, hail and tree sap – all of which can damage glass.
4. Regular Inspection and Maintenance
Inspecting your windshield regularly helps you spot small problems before they become big issues. Look for small chips, surface scratches, or signs of spreading cracks.
Even a small crack can turn into a large one in just a few days, specially in bad weather or on rough roads. If you catch the damage early, a quick and affordable repair can save you from having to replace your windshield completely.
Also, keep your wiper blades clean and in good condition – worn blades can scratch the glass over time and weaken the surface.
Conclusion – How To Repair a Cracked Windshield
It is the fact that the windshield is actually first line of defence against danger and that’s why you should be aware of even a tiny crack or chips.
As well as, windshield make sure about your safety & it maintains your vehicle’s structural strength.
Plus, yes there are many affordable repair options available and insurance often covers the cost, there’s no reason to delay.
Not only this, a NHTSA study found that when you replace a windshield with ADAS sensors then it can cost over $1,000 while it’s repair costs are typically below $150 and if it is done by yourself then you can do it within the $20 to $30 easily, which is why early repairs are really cost-efficient.[¹]
So, now if you still have any kind of unsolved questions then you are welcome in the comment box.
Frequently Asked Questions
Q1. Can a cracked windshield get fixed?
Answer: Yes, a cracked windshield can be repaired, but it depends on the size, depth, location and type of crack. Small cracks (usually less than 6 inches long) and tiny chips (smaller than a coin) can often be repaired with a professional windshield repair service or a DIY repair kit. These repairs involve injecting a special resin into the crack to seal it, stop it from spreading and restore the glass’s strength. However, if the crack is very deep, longer than 6 inches, near the edge of the windshield, or directly in the driver’s line of sight, it may not be safe to repair. In such cases, replacing the entire windshield is usually recommended. It is important to repair the crack quickly, because once it becomes too large or begins to spread outward, the glass loses its structural strength and becomes unsafe to drive.
Q2. Will super glue stop a windshield crack from spreading after?
Answer: Super glue is sometimes used as a temporary emergency measure to stop a windshield crack from spreading, but it is not a permanent or recommended solution. The idea is that applying a very small amount of clear super glue to the crack will seal the crack enough to hold it together until it is properly repaired. However, super glue is not made for glass repair and does not adhere as well as windshield resin. It does not warp or expand with temperature changes like professional resin. Over time, the glue can break down, crumble, or make the damage worse by preventing the proper bonding of the resin during a later repair. If you must use super glue in an emergency, clean the area first and only use a small drop, but then plan to have the windshield repaired properly as soon as possible. It is always better to use a genuine glass repair kit designed for windshields or visit a professional technician.
Q3. Does clear nail polish fix a cracked windshield?
Answer: Clear nail polish is sometimes used as a temporary solution to seal small chips or cracks in the windshield, but this is not a professional solution and should not be relied upon long-term. People use it because it is transparent, dries quickly and prevents dirt and moisture from entering by slightly filling in the damaged area. It may also slow the spread of the crack for a short time. However, clear nail polish does not have the strength, flexibility, or adhesion of professional windshield repair resin. Its color may also change over time and the crack may be difficult to repair later. If you are in a situation where you cannot access a repair kit or technician immediately, applying a small coat of clear nail polish may buy you some time, but it is very important to get the crack repaired correctly as soon as possible. For best results and long-term protection, always use a windshield repair kit or contact a certified repair professional.
References:
[1] Cost and Weight Analysis of Windshields Replacement
https://lindseyresearch.com/wp-content/uploads/2023/05/NHTSA-2011-0066-0103-Windshields-Replacement-Final-Report_30-July-2021.pdf
Guys, I’m a car audio enthusiast and customization expert and I love clear sound and clean installation. Plus, I have spent years helping people build their dream audio setups. And whenever I’m working on cars, I probably listen to music and thinks about the next big upgrade.