Don't Buy Glass Cleaner on a 'Streak Free' Promise Alone

“Streak-free” tells me what a glass cleaner promises after wiping—not whether it is compatible with every window coating, aftermarket film, or mirror backing. I compare seven cleaners and show how I separate marketing claims from manufacturer guidance, ingredient disclosures, and performance tests before buying. Using Windex Original, Windex Ammonia-Free, a non-HeatLock Andersen window, and Security Mirror Industries care instructions as key examples, I examine why one cleaner may be approved for one surface yet conflict with another surface’s care rules. I also cover the HeatLock exception, film requirements, mirror application restrictions, defensible buying options, and nine checks I use before making a purchase. My final rule is simple: I don’t buy on a “streak-free” promise alone—I verify the exact surface, coating, film, backing, ingredients, and required application method first. 0:00 The one-bottle problem 1:16 Seven cleaners compared 3:21 Three types of evidence 3:48 What performance tests prove 5:37 Andersen window cleaner rules 7:16 The HeatLock exception 7:42 Aftermarket film requirements 9:05 Mirror backing restrictions 11:16 Defensible buying options 12:32 Nine pre-purchase checks 13:31 The final purchase rule #GlassCleaner #WindowCleaning #MirrorCleaning #HomeMaintenance #CleaningTips #ProductComparison