Understanding the AS-1 Line
Most states reference the AS-1 line when describing windshield tint limits. Learn what it is and why it matters.
What is the AS-1 Line?
The AS-1 line is a marking placed on your windshield by the manufacturer. It indicates the top portion of the windshield where tint may be applied in accordance with Federal Motor Vehicle Safety Standards (FMVSS). The marking “AS-1” is typically etched or printed in a small area near the top edge of the windshield.
The AS-1 designation means the glass meets certain safety standards for light transmission and optical clarity. When state laws say “non-reflective tint allowed above the AS-1 line,” they mean you can apply tint only on the portion of the windshield above where this mark is placed.
Where is the AS-1 Line Located?
The AS-1 line is typically located approximately 5 to 6 inches from the top of the windshield. However, the exact position varies by vehicle manufacturer and model. To find it on your vehicle:
- 1 Look at the top edge of your windshield near the rearview mirror area.
- 2 Search for small text etched into the glass — you should see markings like “AS-1” or “AS1” along with the manufacturer logo.
- 3 If you cannot find the AS-1 mark, a general rule is to measure 5 inches down from the top of the windshield — this is the approximate area most states allow for tinting.
Why Does the AS-1 Line Matter?
Legal Compliance
Nearly every state references the AS-1 line in their windshield tint regulations. Tinting below the AS-1 line on your windshield is illegal in most states without a medical exemption. Check your state’s specific rules.
Safety
The area below the AS-1 line is critical for driver visibility. Tinting this area too dark can significantly impair your ability to see the road, especially at night or in bad weather conditions.
Vehicle Inspections
In states that require vehicle inspections, tint below the AS-1 line can cause your vehicle to fail inspection, requiring costly removal and reapplication.
States That Reference “Top 5 Inches” Instead
Some states use “top 5 inches” or “top 6 inches” instead of referencing the AS-1 line directly. In practice, this is very similar since the AS-1 line is usually 5–6 inches from the top. States using specific measurements include Alabama, Colorado, Oklahoma, and Texas, among others.
Always check your state’s exact wording to be sure.