Washington window tint law: what is legal on each window

The 24% limit applies to the window, not the film. RCW 46.37.430(2)(b) defines net film screening as both the material the manufacturer applied to the glass and any film added later. So a film's label tells you about the film. It does not tell you what the finished window lets through.

A rough estimate multiplies the two, because light has to pass through both. Shade labels are also rounded, so a film sold as 35% can measure a little under 35%. The inputs below are examples, not figures for any real vehicle or film.

The last row falls under the limit with a film most people would call a 35. That is why "35% is legal" is not a safe statement, and factory glass with shading of its own leaves less room still. What counts is what the actual window lets through, and only a reading taken on that window settles it.

Reflectance is a separate test

Reflectance is the share of light the film reflects outward, and it must be 35% or less. A film can pass on light and still fail on reflectance, so check both. Mirror finish products are not permitted at all.

A window tint percentage is visible light transmission, or VLT: the share of outside light that gets through. The lower the number, the darker the window. Legal tint in Washington depends on the window and the vehicle, so there is no single legal window tint percentage for a whole vehicle.

In this table, windows held to 24% means the side and rear glass of a passenger car and the front side windows of a listed class. Commercial vehicles are separate.

What is the darkest legal tint in Washington?

On a passenger car, and on the front side windows of a listed class, it is whatever film still leaves the window at 24% or more, net. Behind the driver on a listed class, the statute sets no lower percentage, but reflectance must stay at 35% or less and black material is not permitted.

Is 20% tint legal in Washington state?

Not on the side or rear windows of a passenger car, and not on the front side windows of a listed class, unless a physician's written verification applies. A film rated at 20% is below 24% before the factory glass is counted. It can be legal on windows to the rear of the driver on a listed class. The same goes for 5%.

Not automatically. The statute never mentions SUVs. It covers "any vehicle identified by the manufacturer as a truck, motor home, or multipurpose passenger vehicle" as defined in 49 CFR 571.3. The test is how the manufacturer identifies that vehicle, not what the badge or the advertising calls it.

Under those federal definitions, a multipurpose passenger vehicle is designed to carry 10 people or fewer and is built either on a truck chassis or with special features for occasional off-road operation. A truck is designed primarily to carry property or special purpose equipment. A passenger car also carries 10 or fewer, so seat count will not settle it.

The statute does not say where to look. One place to start is the manufacturer's certification label, next to the driver's seat on the door post or door edge. Federal rules have it state the vehicle's type classification, such as truck or MPV (49 CFR 567.4). That is a starting point, not a ruling. For a vehicle you are unsure about, the WSP Equipment and Standards Section is at (360) 596-4017 and equipment@wsp.wa.gov.

The 24% figure does not apply here. RCW 46.37.430(5)(e) allows two things:

• A strip along the top edge. The product must be transparent, cannot extend into the AS-1 portion of the windshield, and cannot extend more than six inches from the top. The AS-1 mark is usually printed on the glass near the top corners.
• Clear film that reduces or eliminates ultraviolet light.

The statute does not define "clear," and it gives no percentage for it. Subsection (5) covers film that reduces light "to any degree," so a shade is not allowed on the windshield simply because it is light. It would have to count as clear, and whether a given film does is a question for WSP or an attorney.

You may see 70% quoted for windshields. That number is not in the RCW's windshield text. The 70% in the table above is the federal rule for commercial vehicles.

Film types that are not permitted

• Mirror finish products
• Red, gold, yellow or black material
• Liquid film that is brushed or sprayed on

Factory glass

The film rules do not prohibit shading applied when the glass was made, if it meets federal standards. That protects the factory glass, not film added to it. Film on a front side window still has to leave that window at 24% or more, net, even when the goal is to match darker factory rear glass.

The door-post sticker

A person or business tinting for profit within restricted areas of the glazing system must supply a sticker for the driver's door post, next to the manufacturer's identification tag. It certifies that the job meets the state's standards for light transmission, reflectance and placement, and it must clearly show the installer's business name and state tax identification number.

Commercial vehicles

WSP says commercial vehicles cannot be tinted to the state levels and points to 49 CFR 393.60, which WAC 446-65-010 adopts for motor carriers. Section 393.60(d) allows tint on the windshield and the windows immediately right and left of the driver only if at least 70% of light still passes through the portions of the glass marked to that standard. It does not limit other windows. A vehicle can be a truck by the manufacturer's label and still be a commercial vehicle in use, so settle which rules apply before any film goes on.

Penalties

Operating a vehicle on public highways with film that violates the statute is a traffic infraction. Knowingly installing film in violation is a misdemeanor. Providing or receiving payment, knowing it is for that kind of installation, is a gross misdemeanor.

Checked October 31, 2026. The RCW and WSP pages were read on that date. The federal sections are from the October 1, 2024 edition of the Code of Federal Regulations, so any later federal change is not reflected. Pending bills were not checked.

• RCW 46.37.430, safety glazing and sunscreening
• RCW 46.37.435, unlawful installation
• Washington State Patrol, vehicle and equipment requirements
• WAC 446-65, adoption of federal motor carrier rules
• 49 CFR 393.60, commercial vehicle glazing
• 49 CFR 571.3, vehicle definitions
• 49 CFR 567.4, the manufacturer's certification label

This page covers window film. Subsection (6) of the statute has separate allowances for required decals, sunscreening devices and recreational products behind the driver.

This is general information, not legal advice, and Silver Diamond Detail is not a law firm. If this summary and the statute differ, the statute controls. For a ruling on a specific vehicle, ask WSP or an attorney.