A scratch on a windshield is not always a reason to replace the glass. Some are shallow enough to polish out; others go too deep or sit where they matter. The first step is telling the two apart.
How do I tell a light scratch from a deep one?
Run your fingernail lightly across the scratch at a right angle. If your nail glides over it without catching, it is a light surface scratch that may polish out. If your nail drops into it or catches, the scratch is deeper and usually needs inspection or replacement. A scratch in the driver’s primary line of sight — the area swept by the wipers directly in front of you — should be looked at regardless of depth.
How are light scratches polished out?
- Clean the glass. Wash and dry the area so no grit gets dragged across it.
- Mask around it. Tape off the surrounding trim and paint.
- Apply a glass polishing compound. Use a compound made for automotive glass with a felt pad on a low-speed buffer, keeping the area wet.
- Work in short passes. Polish for short intervals and check the glass often.
- Stop if it distorts the view. Over-polishing thins the glass and can create a lens effect. If the scratch is not fading, stop — a replacement is the safer call.
What should I not do?
- Household abrasives. Scouring powder, baking soda paste and steel wool scratch or haze the glass.
- Toothpaste. It is a mild abrasive that cannot remove a real scratch and can haze the glass with rubbing.
- Heavy grinding. Aggressive pads and high speed heat and thin the glass, causing optical distortion.
- Polishing the camera area. The aperture in front of the rearview mirror is optically critical — polishing there can affect what the camera sees.
What causes windshield scratches?
- Worn or wrong-size wipers running dry across the glass.
- Dry wiping dust, pollen or sand off dry glass with a wiper or cloth.
- Metal ice scrapers or a dry razor blade on stuck sap.
- Road sand and grit thrown up and caught under the blade.
Replacing wipers every 6 to 12 months and never wiping dry glass prevents most scratches. See our wiper size guide for the right blades.
When does a scratch need replacement?
A scratch your fingernail catches in, one in the driver’s line of sight, one that distorts the view, or one in the camera area usually means a windshield replacement. A shallow chip alongside the scratch may still be repairable — we assess both and tell you honestly which is safe.