California treats the front windows differently from the rear. Its clear UV-film exception has several conditions, so a single tint percentage does not tell the whole story. This guide is supported by the current official Vehicle Code and Highway Patrol guidance.
Read the official sources ↓Rules by window
| Window | Requirement |
|---|---|
| Windshield | Transparent material may cover the topmost portion under the measurement and glare rules in Vehicle Code 26708(c). The statute uses a 29-inch seat-based measurement, not a universal four-inch strip. A separate medical provision addresses qualifying clear UV film. |
| Front side | Qualifying clear, colorless UV material: at least 88% material VLT and at least 70% combined glass-plus-material VLT, with the safety-standard, certification and condition requirements in 26708(d). |
| Rear side | CHP guidance permits any darkness on side windows behind the driver, subject to its color restrictions and other applicable equipment rules. |
| Rear window | CHP guidance permits any darkness when the vehicle has an exterior rearview mirror on each side. The statutory mirror exception requires each mirror to provide a view at least 200 feet behind the vehicle. |
Why 70% alone is misleading
Current Vehicle Code 26708(d) sets separate requirements for the added material and the completed window. The material must transmit at least 88% of visible light. The glazing with that material applied must transmit at least 70% and meet Federal Motor Vehicle Safety Standard 205, including the specified AS-14 abrasion-resistance requirement.
The material must be clear, colorless and transparent, and designed to improve protection against ultraviolet A rays. Damaged material that prevents clear vision must be removed or replaced. A film's advertised percentage does not establish the finished window's compliance.
Windshield strip, colors and reflectivity
Section 26708(c) locates the strip's lower edge at least 29 inches above the undepressed driver's seat, measured from a point five inches ahead of the bottom of the backrest. The seat must be fully back and down, with the vehicle on level ground. The strip must be transparent, cannot be red or amber, cannot have opaque lettering, and must not distort vision or primary colors through other lettering.
The strip cannot reflect sunlight or headlight glare toward other vehicles more than the windshield would without it. Separately, CHP's General Order 100.5 describes rear-window tint as excluding red, yellow and blue. The windshield strip and rear tint have different color restrictions; use the rule for the window being treated.
The sources reviewed do not establish one numerical reflectivity limit for all ordinary tint film. The separate limit for removable medical screening devices does not establish a limit for ordinary tint film.
Vehicle classes and mirrors
The ordinary aftermarket rules discussed here do not supply different front-side VLT limits for a passenger car and an SUV. Rear-window tint depends on having both exterior mirrors. Factory glazing, replacement glazing and specialized commercial vehicles can have additional safety requirements.
Keep the required certificate
For the front-side clear-film exception, the driver must have a certificate in their possession or in the vehicle. When a company installs the material, its signed certificate must confirm that the completed windows satisfy the exception and identify the installer and material manufacturer by full name and street address. An owner-installed application instead requires the manufacturer's signed certificate covering installation according to its instructions.
Medical provisions are specific
Section 26708(e), added by AB 1303, allows qualifying clear, colorless UV material on the windshield, side or rear windows with a licensed dermatologist's certificate. It retains the 88% material and 70% completed-window thresholds, safety-standard requirements and clear-vision condition. The certificate must explain the medical need to avoid ultraviolet exposure and be carried by the driver or kept in the vehicle. It is not a general exemption for dark windshield film.
A different provision covers removable front-side screening devices for documented medical or visual conditions. CHP says those devices cannot be used during darkness and that permanent tint film does not qualify under that removable-device exception. No California DMV application process was verified in the sources reviewed.
Source review and effective dates
The current official Vehicle Code 26708 was read on October 14, 2026. Its amendment note identifies SB 506, Chapter 417, Statutes of 2025, Section 5, effective January 1, 2026. That amendment concerns commercial-vehicle safety technology; the current text retains the clear-film requirements summarized here.
The medical clear-film provision was added by AB 1303, effective January 1, 2018. No California measurement tolerance or current statewide tint fine is claimed here. Check the linked current code and CHP before choosing or changing an installation. This is general information, not legal advice or a compliance guarantee.
Common installation questions
What should I check before adding film to the front windows of a car or SUV?
Ask about both the material and the finished window. California’s clear UV-film exception requires clear, colorless material with at least 88% light transmission and at least 70% through the glass and material together. The exception also has safety-standard and certificate requirements. The ordinary front-side rule does not provide a different percentage for an SUV. Ask the installer to explain how the completed windows meet all of these conditions and provide the required certificate.
Official sources: California Vehicle Code 26708: current official code ↗
How far down can a windshield strip extend?
California uses a seat-based measurement rather than one fixed strip depth. The strip’s lower edge must be at least 29 inches above the undepressed driver’s seat, measured from a point five inches ahead of the bottom of the backrest, with the seat fully back and down and the vehicle level. The material must also meet the statute’s transparency, color, lettering and glare conditions. Have the installer check that measurement on your vehicle.
Official sources: California Vehicle Code 26708: current official code ↗
What does the medical provision allow on the windshield?
The medical clear-film provision requires a licensed dermatologist’s certificate explaining the need to avoid ultraviolet exposure. It allows qualifying clear, colorless UV material subject to the 88% material and 70% finished-window transmission thresholds, safety standards and clear-vision condition. Keep the certificate with the driver or in the vehicle. This provision does not authorize a dark full-windshield film; the separate removable front-side screening exception has its own conditions.
Official sources: California Vehicle Code 26708: current official code ↗ · CHP General Order 100.5: Regulated Devices ↗
Before you rely on this guide
This is general information, not legal advice, a vehicle inspection, or permission to install a particular film. Exceptions and enforcement procedures can depend on your circumstances.
- The review date records a source check, not attorney review, human legal approval or a guarantee that no later law applies.
- No numerical California enforcement tolerance, universal film-reflectivity cap, or current statewide fine was verified.
- Specialized vehicles and removable screening devices require separate analysis; their exceptions are not a general permission for dark front-window film.
The research date shows when the sources were checked. It is not the date the law took effect, and it does not mean this page is monitored continuously. This research preview still awaits human editorial review; we do not claim attorney review.
Official sources
- California Vehicle Code 26708: current official code ↗
Full current consolidated section read on October 14, 2026. The amendment note identifies Stats. 2025, Ch. 417, Sec. 5 (SB 506), effective January 1, 2026. Subdivisions (b)(4), (b)(8), (b)(10), (c), (d) and (e) support the summarized exceptions and conditions.
- SB 506, Chapter 417, Statutes of 2025: official chaptered text ↗
Chaptered October 6, 2025. Section 5 reproduces Vehicle Code 26708; the commercial safety-technology amendment is also described in the Legislative Counsel’s Digest.
- AB 1303, Chapter 210, Statutes of 2017: official chaptered text ↗
Full official historical text read. Vehicle Code 26708(b)(4), (b)(8), (b)(10), (c), (d) and (e) support the detailed rules; this is the 2017 enactment, not a current consolidated code page.
- CHP General Order 100.5: Regulated Devices ↗
Revised December 2023. Annex D, pages 30–31, covers aftermarket rear-window tint, colors, dual exterior mirrors and the removable medical-device distinction.
- CHP frequently asked questions: vehicle modification ↗
Official public guidance distinguishes the clear front-side UV-material exception from ordinary aftermarket tint and notes dual mirrors for tinted rear glass.
- California Assembly Transportation Committee: 2017 legislation summary ↗
Official retrospective summary of AB 1303 confirms the clear-film medical provision and its 88% material threshold.
- Judicial Council: 2017 court-related legislation summary ↗
AB 1303 entry identifies January 1, 2018 as its effective and operative date.
- CHP: 2026 windshield-mounted commercial safety technology bulletin ↗
March 24, 2026 bulletin confirms an amendment to 26708 effective January 1, 2026. It addresses commercial safety devices and does not reproduce all tint provisions.