California window tint law: everything you need to know

Last reviewed October 2026 against California Vehicle Code sections 26708 and 26708.2.

Key takeaways

• Your windshield can carry transparent, non-red, non-amber material only at the very top.
  
• Front side windows allow only clear, colorless film that rates 88% VLT or higher, and the glass with film must still pass 70%.
  
• Rear side windows have no darkness limit, and the rear window has none if your car has outside mirrors on both sides.
  
• Medical exemptions cover removable sun screens or clear film with signed documentation, not darker permanent tint.

California writes its tint rules window by window, and the numbers people repeat online don’t always match the law. We tint vehicles at our Thousand Oaks shop, so we know where drivers get tripped up. This guide walks through each window using the text of the statute itself.

One term first. VLT stands for visible light transmission, the percentage of visible light that passes through the glass and film. A higher VLT means lighter tint.

California window tint rules at a glance

California windshield tint rules

The statute lets you apply transparent material to the topmost portion of the windshield, and it sets four conditions:

• The bottom edge of the material has to sit at least 29 inches above the driver’s seat. You measure from a point five inches in front of the bottom of the backrest, with the seat in its rearmost and lowest position, on level ground.
• The material cannot be red or amber.
• The material cannot carry opaque lettering, and any other lettering cannot distort vision through the glass.
• The material cannot reflect sunlight or headlight glare into other drivers’ eyes any more than the bare windshield does.

Many guides, and some shop websites, quote a flat “4 inches” limit. The statute text does not use that number. It uses the 29-inch measurement, so measure your own car and skip the rule of thumb.

The AS-1 line etched near the top corners of your glass marks where factory tint stops. The statute does not treat it as the legal boundary, so a strip that reaches the AS-1 line does not automatically pass.

What about film over the whole windshield? California allows it only when the film is clear, colorless, and transparent, and when all of these are true:

• The film rates at least 88% VLT.
• The glass with film still meets federal safety standard FMVSS 205, including the 70% light transmittance minimum and AS-14 abrasion resistance.
• The film is designed to block UVA rays.
• A licensed dermatologist has certified that you should not be exposed to ultraviolet rays because of a medical condition.

Front side window tint rules in CA

This is the rule that trips up the most drivers. You will often hear “California requires 70% tint on the front windows.” The statute says something different and more specific.

The law allows only clear, colorless, transparent film on the front side windows, and it sets two numbers:

1. The film itself has to let in at least 88% of visible light.
2. The glass with the film applied has to keep at least 70% light transmittance.

Factory glass already blocks some light, so the film and glass work as a stack. Here is an illustrative example: glass that passes 85% of light, plus film that passes 88%, produces a combined reading of roughly 75%. That passes. Glass that starts near 78% would push the same film below 70%.

The statute adds two more conditions:

• The film has to enhance the glass’s ability to block UVA rays.
• If the film tears, bubbles, or wears enough to affect clear vision, you remove or replace it.

Want to choose shades for your other windows? Read our guide to window tint darkness.

Rear side windows and rear window laws in California

California gives you the most freedom here.

• Rear side windows (the ones behind the driver) fall outside the statute’s tint restrictions, so any darkness works.
• The rear window also allows any darkness, if your car has outside mirrors on both the left and right sides. Those mirrors have to show you the road for at least 200 feet behind the vehicle. Nearly every modern car meets this.

Many SUVs, trucks, and EVs come with factory privacy glass on these windows. Factory tint on rear windows does not create a problem under this section.

Banned colors and reflectivity

Two rules cover appearance.

Color. Windshield material cannot be red or amber. Front side film has to be clear and colorless, which rules out color shifts and tinted hues entirely.

Reflectivity. Windshield material cannot bounce sunlight or headlight glare into other drivers’ eyes any more than the bare glass does. In plain terms, no mirror finishes on the windshield. The 35% reflectivity figure you may see quoted applies to medical sun screens, which we cover below.

Medical exemptions: two paths

California allows medical exceptions, and the statute splits them into two distinct paths. Neither one authorizes darker permanent tint on your front windows.

Path 1: removable sun screens

Sun screening devices can go on the front side windows (either side of the front seat) if the driver or a front-seat passenger carries one of these:

• A signed letter from a licensed physician and surgeon certifying that the person needs shade because of a medical condition.
  
• A signed letter from a licensed optometrist certifying that the person needs shade because of a visual condition.

You cannot use these devices during darkness. Each device has to meet these specs:

Path 2: clear film with a dermatologist certificate

A licensed dermatologist can certify that you should not be exposed to ultraviolet rays because of a medical condition. With that certificate in your vehicle, you can apply clear, colorless, transparent film to the windshield, side windows, or rear windows. The film still has to rate 88% VLT or higher, meet the federal glazing standard, and block UVA. If it tears or bubbles, you replace it.

Questions about your windows? Call us at (805) 870-8004 or request a free quote.

VLT, factory tint, and your vehicle type

Every reading you take on your car includes the glass. Your factory glass counts toward the numbers above, so two cars with identical film can read differently.

• Sedans usually come with clear glass all around, so you start with the most room on the front windows.
• SUVs, trucks, and vans often carry privacy glass on the rear windows, which stays exempt from the tint limits.
• Teslas and other EVs often ship with darker glass, including some panoramic roofs. Have a shop measure the front glass before you choose film.

Learn more about the film we install on our window tinting service page.

Is 5%, 20%, 35%, 50%, or 70% tint legal in California?

Lower numbers mean darker film, so 5% is the darkest and 70% is the lightest. Here is how each percentage plays out:

• Rear side windows and rear window: any of these work. The rear window needs outside mirrors on both sides.
• Front side windows: none of these work as film. The film has to rate 88% VLT or higher, and it has to be clear and colorless.
• Windshield strip: the statute sets no percentage. It sets the conditions we covered above.

Ceramic film and staying legal

Ceramic film blocks heat and UV with nano-ceramic particles instead of dark color. That means you can get strong heat and UV performance without going dark. It also does not interfere with GPS, radio, or cell signals the way metallic film can.

We use XPEL PRIME XR PLUS nano-ceramic film, which blocks over 99% of UV rays. 

Some shops market one tint level for every window. We treat each window as its own decision, because the front and rear windows play by different rules.

Tickets, enforcement, and how officers measure

Section 26708 opens with a blunt rule: you cannot drive with material applied to the windshield or side or rear windows unless an exception covers it. The exceptions we walked through above carry the conditions.

Officers can check tint with a meter. The meter reads the light passing through your glass and film together, so your factory glass counts in the result. An officer who finds a violation can write you a citation.

We can’t quote a penalty here. The amount depends on your citation and your history, so check with the court that handles your ticket.

Professional installation vs. DIY

You can buy tint kits at an auto parts store, but the front windows leave less room for error. A professional install handles the parts of the statute that DIY skips:

• Precision cutting. We plot-cut each piece with XPEL’s DAP software, which prevents blade marks on your glass.
• A meter check. We read the combined result before the car leaves the shop.

Tyler O’Hara, a 2x XPEL Gold Medalist, leads every install. Poor film and rushed installs also cause bubbling, which we cover in our post on why window tint bubbles.

Buying a used car or moving to California

Tint you did not install carries the same rules, so check it before you commit to the car.

• Check the film’s condition. Bubbles, peeling, and tears on front film mean replacement under the statute.
• Get a meter reading. A shop can measure the front glass and film together.

If you move here with a tinted car, use California’s rules as your baseline and have a shop measure the front windows.

California window tint law FAQ

What is the darkest legal tint in California?

Rear side windows and the rear window allow any darkness, and the rear window needs outside mirrors on both sides. Front side windows allow only clear, colorless film at 88% VLT or higher.

Is 35% tint legal in California?

35% film works on rear side windows and the rear window. It does not work as film on front side windows.

Will an officer cite 50% tint?

On the front side windows, 50% film falls below the 88% film requirement, so an officer can cite it. On the rear windows, no darkness limit applies.

Is 20% or 35% tint darker?

20% is darker. Lower VLT numbers mean less light passes through.

Can I tint my full windshield?

Only with clear, colorless, transparent film that rates 88% VLT or higher, and only with a licensed dermatologist’s certificate in the vehicle. Otherwise, you limit material to the topmost portion of the windshield.

Do I need a certificate for my tint?

For clear film on your front side windows, yes. The installer signs it, or the manufacturer signs it if you installed the film yourself, and it stays in the vehicle.

Do medical exemptions allow dark front window tint?

No. Exemptions cover removable sun screens, which you cannot use at night, or clear film with a dermatologist’s certificate. For more answers, see our window tinting FAQs.

Get your tint done right

We help drivers across Thousand Oaks, Westlake Village, and the Conejo Valley choose film that fits every window. Tyler O’Hara, our 2x XPEL Gold Medalist, will measure your glass and walk you through your options. Call us at (805) 870-8004 or request a free quote.

Sources: California Vehicle Code section 26708 and section 26708.2.

This guide is informational and does not replace legal advice. Confirm current rules with the California Vehicle Code or your local court.