How do I stop a crack in the windshield from spreading?

I've heard super glue works as a temporary fix. They also make windshield repair kits, Erica. Check in an auto parts store.

I, also heard that super glue works for a bit but for safety, getting it replaced is the best answer if the crack is spreading.

Check with your car insurance. Our windshield was replaced very cheaply.

Use the windshield repair kits from auto parts store.

Depending on the crack and, amazingly, where you live - you may be able to do the superglue trick, but that is a Band-aid at best. If you live in a part of the country where heat and cold happen frequently in the spring and summer, you need to replace the glass - no matter what you do it will spread. Your insurance should cover the cost or at least most of it. Every state I know of will not allow your vehicle to pass inspection with a cracked windshield. Safelite is a really good company that we have used - we live in an area that gets lots of hail.

You should never try to repair a crack in a windshield. Chips can be repaired with the repair kits mentioned above but a crack affects the structural integrity of the windshield and for safety reasons you should have the windshield replaced.

Clear nailpolish

Try Gorilla Glue. If the crack is not in the windshield wiper area, it’s legal here...but to prevent heat from causing it to crack more, leave your car windows down just a tiny bit, barely visible, to lower the temperature inside the car. Also, the folding foil sunscreens do work to keep your interior cooler...auto parts stores or big box stores carry them.