This is the most famous DIY fix. Clean the crack with a microfiber cloth and a drop of rubbing alcohol. Apply a thin layer of over the entire crack. Let it dry completely, then add a second coat.
While it's not always possible to completely stop a windshield crack from spreading, there are some methods that can help slow down or temporarily halt its progression. Here are a few: can you stop a windshield crack from spreading
A professional windshield repair technician can assess the damage and provide a more permanent solution. They may use advanced techniques, such as: This is the most famous DIY fix