Use a commercial anti-fog spray

Spray a dedicated anti-fog product onto a clean mirror and buff it dry. These sprays use concentrated surfactant and polymer formulas that outlast DIY methods, keeping the mirror fog-free for 2-4 weeks per application.

Steps

1. Clean the mirror with glass cleaner and dry it thoroughly.
2. Spray a light, even coat across the entire surface from about 15 cm (6 inches) away.
3. Buff gently with a clean microfiber cloth until the mirror is clear.

Why It Works

Commercial anti-fog sprays deposit a hydrophilic polymer layer that causes moisture to condense as a uniform transparent sheet rather than light-scattering droplets. The polymer bonds more durably to glass than household soap, so the coating lasts longer between applications.

Tips

• Rain-X Anti-Fog ($5-8) and Hendlex Anti-Fog ($10-15) are widely available and well-reviewed
• These products also work on glass shower doors, car windshields, and eyeglasses
• Apply to a freshly cleaned mirror for the best adhesion and longest life
• Avoid wiping the treated mirror with cleaning products between applications, as this strips the coating