California Vehicle Code § 26708 governs window tint on motor vehicles registered in California. The front side windows must transmit at least 70 percent of visible light as a combined glass-plus-film system (the floor comes from Federal Motor Vehicle Safety Standard No. 205, incorporated through § 26708.5), and material applied to those windows must itself transmit at least 88 percent of visible light (§ 26708(d)(1)). The windshield may carry non-reflective material only above a line measured 29 inches above the undepressed driver's seat (§ 26708(c)(1)). Darkness behind the front seats is not regulated.
Below: each window position with the subdivision that controls it, the two medical-exemption provisions and what each actually permits, the current fix-it-ticket schedule, and the specific errors most commonly repeated about this statute. Statute and interpretation are kept visibly separate — the Sources section at the end lists the exact subdivisions used.
Understanding VLT (Visible Light Transmission)
Window tint darkness is measured by Visible Light Transmission (VLT)—the percentage of visible light that passes through the window. A higher VLT percentage means more light passes through (lighter tint), while a lower percentage means less light passes through (darker tint).
Importantly, California's VLT requirements apply to the combined effect of the tint film and the factory glass. Since factory glass typically blocks 15-25% of light already, this affects what film you can legally apply. This is why professional installation matters—shops like ours measure and verify VLT to ensure compliance.
California Window Tint Laws by Window Position
| Window | Legal Requirement | Notes |
|---|---|---|
| Front Windshield | Non-reflective material only, bottom edge ≥29" above the undepressed driver's seat | CVC 26708(c)(1) |
| Front Side Windows | 70% VLT minimum combined (film + glass); film itself ≥88% VLT | FMVSS 205 + CVC 26708(d)(1) |
| Rear Side Windows | No darkness limit | Not regulated by CVC 26708 |
| Rear Window | No darkness limit | Dual side mirrors required (CVC 26709) |
Front Windshield
California permits non-reflective tint on the topmost portion of the windshield. Almost every guide describes that limit as “the AS-1 line” — but that is the industry convention, not the statute. Vehicle Code section 26708(c)(1) sets a measurement instead: the bottom edge of the material must be at least 29 inches above the undepressed driver's seat, measured from a point five inches in front of the bottom of the backrest, with the seat in its rearmost and lowermost position and the vehicle on a level surface.
The AS-1 line is a marking the glass manufacturer etches into the windshield, and on most vehicles it falls close to where the 29-inch rule lands — which is why the shorthand survives, and why “the top 4 to 5 inches” is a reasonable rule of thumb. It is not the legal test. On a vehicle with an unusually high or low seating position the two can diverge, and it is the 29 inches that an officer and a court are measuring against.
The rest of the windshield must remain clear. Fully transparent UV and infrared films that do not reduce light transmittance below factory levels are a separate matter — see windshield tinting.
Front Side Windows (Driver & Passenger)
California's law is strictest on the front side windows. The combined glass-plus-film system must transmit at least 70 percent of visible light, which in practice means only very light tint is permitted — and in some cases, none at all.
Two numbers govern the front side windows, and conflating them is the most common error in guides on this subject. The 70 percent figure is the combined transmittance of glass plus film and comes from Federal Motor Vehicle Safety Standard No. 205, which California incorporates through § 26708.5. Section 26708(d)(1) separately governs the film itself: material applied to a front side window must have a minimum visible light transmittance of 88 percent. Both are correct; they measure different things. For a complete breakdown of how dark tint can be in California by window position, see our dedicated guide.
Factory glass on a modern vehicle typically transmits around 80 percent of visible light before any film is applied, so a “70 percent film” stacked on top of it lands well below the combined 70 percent floor. The film has to be nearly clear — 88 percent or better — for the finished window to stay compliant. Any shop offering a visibly darker front-window film is offering a fix-it ticket.
The good news: even 70% VLT ceramic film still provides significant benefits. Our Avery Dennison Encore Supreme ceramic films at 70% VLT still block 99% of UV rays and reject meaningful heat—you just won't see a visible darkening effect.
Rear Side Windows
California places no restrictions on rear side window tint. You can legally apply any darkness level, from 50% (light) to 5% (limo tint). Most customers choose 20-35% for a balanced look that provides privacy and heat rejection without being too dark for nighttime driving.
Rear Window (Back Glass)
Like rear side windows, the rear window can be tinted to any darkness. However, California Vehicle Code Section 26709 requires that if the rear window is tinted dark enough to significantly reduce rearward visibility, the vehicle must have side mirrors on both sides. Most modern vehicles already have dual side mirrors, so this is rarely an issue.
Penalties for Illegal Window Tint in California
Getting caught with illegal window tint in California can be expensive and time-consuming. According to the California Courts Traffic Penalty Schedule, here's what to expect. First offenses are almost always correctable fix-it tickets — but you still pay to remove and replace the film:
Violation Penalties
- 1st Offense:"Fix-it" ticket with $25 base fine ($197+ total with fees). Must remove/replace tint and have correction verified.
- 2nd Offense:Higher fine (typically $100+ base) plus all applicable fees. No longer eligible for fix-it ticket.
- Repeat Offenses:Can escalate to misdemeanor charges. May affect insurance rates.
Beyond fines, illegal tint can make you a target for traffic stops and may complicate insurance claims if tint is deemed a factor in an accident. The simplest solution is to work with a professional shop that ensures compliance from the start.
Medical Exemptions for Window Tint
California's medical exemption is two separate provisions, and the widely-repeated summary — “a doctor's note gets you darker front tint” — is wrong about what either one actually permits. Neither authorises a specific darker VLT on film.
CVC § 26708(e) — the dermatologist route
Permits clear, colorless, transparent material with a minimum 88 percent visible light transmittance, applied to glass meeting FMVSS No. 205. That is the same 88 percent the general film rule already requires, so this subdivision authorises no additional darkness — what it authorises is UV-blocking material on glass it would otherwise not be permitted on. The certificate must be signed by a licensed dermatologist. Material must be removed or replaced if it tears, bubbles, or wears enough to obstruct clear vision.
CVC § 26708(b)(10) — the sun-screening-device route
Permits sun screening devices meeting § 26708.2 — not window film — on the side windows beside the front seat. A signed letter is required from a licensed physician and surgeon (for a medical condition requiring shade from the sun) or a licensed optometrist (for a visual condition requiring the same). The devices may not be used during darkness.
A note from a general practitioner is not automatically either signatory, and a roll of darker film is not a sun screening device under § 26708.2. Our California tint medical exemption guide keeps the two provisions separate and names what each one actually permits.
Tips for Staying Legal While Maximizing Benefits
Just because front windows are limited doesn't mean you can't enjoy significant benefits from window tinting. Here's how we help Sacramento drivers maximize protection while staying compliant:
- Use ceramic film on front windows: Even at 70% VLT, ceramic film blocks 99% of UV rays and provides meaningful heat rejection. You get the health benefits without visible darkness.
- Go darker on rear windows: Since there are no restrictions, we recommend 20-35% VLT for rear windows. This creates a gradual transition that looks intentional while providing privacy and heat rejection where it matters most.
- Consider windshield strip: A 4-5 inch strip at the top of your windshield is legal and helps reduce glare during sunrise and sunset driving.
- Work with a professional shop: We measure actual VLT after installation to verify compliance. This documentation can be valuable if you're ever questioned.
Why Choose Quality Window Tinting for Legal Compliance
At Quality Window Tinting, we've been helping Sacramento drivers navigate California's tinting laws for over 20 years. Our experience means you get:
- • Expert knowledge of current California Vehicle Code requirements
- • VLT measurement and verification for every installation
- • Documentation you can keep in your vehicle
- • Guidance on medical exemptions if applicable
- • Premium Avery Dennison Encore films (also SunTek certified) available in compliant VLT levels
- • Lifetime warranty on all installations
Don't risk fines and the hassle of removing illegal tint. Contact us for a free consultation and we'll help you maximize the benefits of window tinting while staying 100% legal.
Which applies to you
| If this is you | What we suggest |
|---|---|
| You want a noticeably darker look on the front windows | Not available legally in California. 70% VLT is the statutory floor for front side windows and no shop can lawfully go darker without a medical exemption. Any shop that offers to is handing you a fix-it ticket. |
| Your main problem is heat, not appearance | Front window darkness is beside the point. Heat rejection depends on the film’s infrared performance, not its visible darkness — a 70% VLT ceramic film rejects far more heat than a dark dyed film, while staying legal. |
| You want privacy for passengers or cargo | Go as dark as you like. California places no limit on rear side windows or the back glass, so the privacy you are after is fully available behind the front seats. |
| You have a diagnosed light-sensitive condition | The medical exemption does not grant darker film. CVC 26708(e) permits clear 88% UV-blocking material (dermatologist signature); 26708(b)(10) covers sun screening devices rather than film (physician or optometrist signature). See the medical exemption guide for which provision applies and what documentation to carry. |
| You bought the car with tint already on it | The ticket follows the driver, not the installer. Have the front windows measured before you are pulled over — a meter reading takes a minute and tells you where you stand. |
Common mistakes
Assuming 70% VLT means the film is 70%
The law governs the finished result — film plus glass together — not the film on its own. Factory glass already absorbs roughly 15–25% of visible light before any film is applied, so a "70%" film on top of it will not measure 70% at the window. This is the single most common way a well-intentioned installation ends up illegal.
Believing rear windows have a legal limit
They do not. California regulates the windshield and the front side windows and stops there. Drivers routinely pay for lighter rear film than they actually wanted because they assumed a limit existed. The one related requirement is that a vehicle with a dark rear window must have working side mirrors on both sides — which nearly every modern car already does.
Treating a fix-it ticket as a one-time nuisance
A first offense is correctable, but the correction has to be verified, which means paying to remove film you already paid to install and then paying again for compliant film. The removal is the expensive part. Getting the front windows right the first time costs nothing extra.
Reading another state’s rules and assuming they apply
Tint law varies widely between states and California is among the strictest on front windows. Figures you find for Arizona, Nevada or Washington are not transferable. If you moved here with a legally tinted car, it may not be legal now.
Bottom line
California gives you almost no latitude on the front windows and almost total latitude behind them. That is the whole law in one sentence. The practical consequence is that if you are tinting for heat, glare or UV — which is most people — the 70% front limit costs you far less than it appears to, because those benefits come from the film’s infrared and UV performance rather than from how dark it looks. Choose film on its specifications, go dark in the back, and have the front measured after installation.
Sources
Every legal statement on this page comes from the California Vehicle Code. The sections used, and what each one governs:
- Vehicle Code § 26708 — the operative section. Subdivision (c)(1) sets the 29-inch windshield measurement; (d)(1) sets the 88 percent minimum transmittance for material applied to front side windows; (b)(10) and (e)(4) set out the medical-exemption documentation.
- Vehicle Code § 26708.5 — prohibits transparent material that alters colour or reduces light transmittance except as section 26708 permits, and covers factory tinted safety glass.
- FMVSS No. 205 — the federal glazing standard California incorporates, and the origin of the 70 percent combined figure. This is why 70 and 88 are both correct and are not the same measurement.
- Vehicle Code § 26709 — the side-mirror requirement referenced in the rear-window section.
Statute versus interpretation. The section numbers, measurements and percentages above are what the code says. The practical guidance around them — which film to choose, what an officer is likely to measure, what a correction costs — is our reading as installers, not law. Enforcement varies, and this page is general information rather than legal advice. For a specific vehicle or a medical exemption, confirm with the DMV or an attorney.
Reviewed against the statute: . We re-check this page against the Vehicle Code rather than against other tint sites, because the AS-1 shorthand that circulates almost everywhere is not what § 26708(c)(1) actually says, and the “medical exemption for darker tint” summary that circulates almost everywhere is not what § 26708(e) or § 26708(b)(10) actually permits.