Should Windshield Film Be Applied on the Inside or Outside?
2 Answers
Automotive windshield film should be applied on the inside. Relevant information about automotive window film is as follows: 1. Automotive window film is applied to car glass to control sunlight and ensure safety. In addition to sunlight control, its basic safety features include anti-glare, UV protection, heat insulation, scratch resistance, holding glass fragments together, privacy protection, and ensuring safe driving performance. 2. If automotive window film is applied on the outside of the car glass, it can easily reduce the effectiveness of the film. 3. Applying automotive window film on the inside of the car glass first avoids damage caused by external environmental factors. Secondly, in the event of an accident while driving where the car glass is shattered, the window film will hold the glass fragments together, preventing secondary injuries to the driver and passengers from broken glass shards, thereby enhancing the safety of both the driver and passengers.
The windshield film must be applied on the inside—that's the standard practice. While helping friends with their cars, I've seen too many people make the mistake of applying it on the outside. If installed externally, the wipers can easily shred the film, and exposure to wind and sun will cause it to deteriorate within weeks. The film is designed with specialized adhesive to bond tightly to the glass when applied on the inside, blocking 99% of UV and infrared heat radiation, keeping the car cooler in summer. Interior application also reduces glare, improving visibility and safety. I personally recommend choosing a high-transmittance type—maintaining over 70% light transmission ensures it passes vehicle inspections. Before installation, thoroughly clean the glass with soapy water or a dedicated cleaner to prevent bubbles or air leaks that could affect performance. Hire a professional at a reputable shop instead of DIYing to save money—it’s not worth the hassle. Properly installed film saves on AC costs and extends the lifespan of your interior, making it a win-win.
