There is no proven way to keep a crack in a windshield from growing, but placing clear masking tape on the crack can be helpful until the driver can take the vehicle to a repair shop. Repairing the windshield as soon as possible is necessary to ensure driver safety and the safety of passengers. In some states, it is illegal to drive with a cracked windshield.
Windshield cracks can become bigger with extreme heat or cold, or with the weight of snow. Home remedies like super glue or tape are ineffective and should generally be avoided. Until the crack is repaired, avoid slamming car doors, playing a stereo with powerful bass and hitting speed bumps.