How to Clean Headlights: Step-by-Step Guide

Over time, headlights get a hazy, yellowed film from UV rays, road grime, and oxidation. This not only looks bad but also reduces your nighttime visibility. Cleaning them is a simple DIY task that can be done with common household items or a commercial kit. Before you start, check if your headlights are just dirty or actually oxidized. If the haze is on the surface, a simple wash may work. If it’s deeper, you’ll need to sand or use a chemical cleaner.

What You’ll Need

Dish soap and water
Baking soda
White vinegar (optional)
Microfiber cloths or soft rags
Spray bottle
Toothpaste (non-gel, with baking soda) or a commercial headlight restoration kit
Sandpaper (if using a kit: usually 400, 800, 1000, 2000 grit)
Masking tape and plastic sheeting (to protect paint)
UV sealant or car wax (to protect after cleaning)

Step-by-Step

Wash the headlights – Mix a few drops of dish soap in a bucket of water. Use a soft sponge or cloth to wash the headlight lenses and the surrounding area. This removes loose dirt and grime that could scratch the plastic during cleaning.
Mask off the surrounding paint – Use masking tape and plastic sheeting to cover the bumper and hood around the headlights. This protects your car’s paint from scratches and chemical splashes.
Apply your cleaning agent – If using a commercial kit, follow the instructions for the specific product. For a DIY method, make a paste of baking soda and water (or use toothpaste). Apply it generously to the lens with a soft cloth or your fingers.
Scrub gently – Rub the paste into the lens in circular motions. Focus on the cloudy areas. For heavy oxidation, you may need to apply more pressure, but always start gentle to avoid scratching. Spend about 2-3 minutes per headlight.
Rinse and inspect – Rinse off the paste with clean water. Check if the haze is gone. If not, repeat the scrubbing or move to sanding (if using a kit).
Sand if necessary (optional) – If the haze persists, use fine-grit sandpaper (like 1000 then 2000) wet-sanding in a back-and-forth motion. Keep the surface wet. This removes the oxidized layer. Follow with a finer grit to smooth the surface.
Polish the lens – After sanding, apply a plastic polish or a small amount of toothpaste and buff with a clean microfiber cloth until shiny.
Protect with a sealant – Apply a UV sealant or car wax to the clean lens. This creates a barrier against future oxidation. Buff off any excess after it dries.

Common Mistakes

Skipping the wash – Cleaning a dirty lens with an abrasive paste or sandpaper can scratch the plastic. Always wash first.
Using the wrong sandpaper grit – Starting with too coarse a grit (like 400) on a lightly hazed lens can cause deep scratches that are hard to remove. Always start with the finest grit that works.
Not protecting the paint – Chemical cleaners and sandpaper can damage the clear coat on your car’s paint. Masking is essential.
Forgetting to seal – Without a sealant, the headlights will re-oxidize quickly, often within a few months. Always apply a UV protectant.
Using too much pressure – Pressing hard with a cloth or sandpaper can create uneven surfaces or scratch the lens. Let the abrasive do the work.

Tips

Work on a cool, shaded area – direct sunlight can dry the cleaning agents too quickly, making them less effective.
Use a headlight restoration kit for best results – these kits include multiple grits of sandpaper and a polishing compound designed for headlights.
If you don’t have a sealant, a coat of car wax works well as a temporary protectant.
Clean both headlights at the same time to keep them looking even.
For mild haze, a simple mixture of vinegar and water (1:1) sprayed on and wiped off can help.

Troubleshooting

Haze remains after cleaning. If the lens is still cloudy after scrubbing and sanding, the oxidation may be too deep. You may need to repeat the sanding process with a coarser grit (like 600) and then work back up to finer grits. If it still doesn’t clear, the headlight may need professional wet-sanding or replacement.

Scratches appeared. If you see fine scratches, they are likely from using too coarse a grit or too much pressure. You can try to remove them by sanding gently with a very fine grit (2000 or higher) and then polishing.

Headlights fog up inside. If moisture is inside the lens, the seal is broken. This cannot be fixed by cleaning the outside. You’ll need to remove the headlight assembly, dry it, and reseal it with silicone sealant.

Cleaning made it worse. Sometimes cleaning can reveal deeper damage or cause a white residue. If you used a chemical cleaner, make sure it’s fully rinsed off. If the lens is badly pitted or cracked, cleaning won’t help; replacement is the only fix.

Frequently Asked Questions

Can I use toothpaste to clean headlights?

Yes, non-gel toothpaste containing baking soda works as a mild abrasive. It’s effective for light to moderate haze, but may not be enough for severe oxidation.

How often should I clean my headlights?

It depends on exposure and climate. If you notice reduced clarity or yellowing, it’s time to clean. Regular washing and a coat of wax every few months can prevent buildup.

Will cleaning headlights improve visibility?

Yes, removing the haze can significantly increase light output, improving nighttime visibility and safety.

Can I use a headlight restoration kit on plastic lenses?

Yes, most kits are designed for plastic lenses. They typically include sandpaper, polish, and a sealant. Follow the instructions carefully.

Is it safe to use a drill with a polishing pad?

Yes, but use a low speed and be careful not to overheat the plastic. Many kits include a drill attachment for easier polishing.

Why do headlights turn yellow?

Yellowing is caused by UV radiation from the sun breaking down the plastic, and by oxidation. This is a natural process over time.

Sources: U.S. Department of Energy. Menus and buttons can differ slightly by version. Spotted something out of date? Tell us.