Illinois allows window tint on your car, but only up to a specific darkness level, and the rules differ between front windows, rear windows, and windshields

Illinois measures window tint darkness using visible light transmittance (VLT), which is the percentage of light allowed through the glass. The darker the tint, the lower the VLT number. Front side windows must allow at least 35% of light through. Rear side windows and rear windshields can be any darkness. Your windshield cannot have tint below the manufacturer's AS-1 line — the band at the very top of the glass where the sun visor sits.

The state does not require you to register your tint or get it inspected before installation. However, law enforcement can measure your tint during a traffic stop, and if it falls below the legal limit, you can receive a citation. The fine for illegal tint in Illinois is typically between $100 and $500, though the exact amount depends on the officer and the court.

Medical exemptions exist. If you have a condition that makes you sensitive to sunlight — such as lupus, porphyria, or severe photosensitivity — you can explore for a medical exemption that allows darker tint on front side windows. You will need a letter from a licensed physician stating the medical reason and recommending tint as treatment.

Key Takeaways

  • Front side windows must transmit at least 35% of visible light; rear windows can be any darkness.
  • Your windshield cannot have any tint below the AS-1 line at the top.
  • Illinois does not require pre-approval or registration of window tint before installation.
  • A medical exemption from a physician allows darker tint on front windows if you have a light-sensitive condition.
  • Illegal tint can result in a fine between $100 and $500.

How Illinois Measures Window Tint Darkness

The state uses visible light transmittance (VLT) as the standard. VLT is measured as a percentage: 100% means no tint at all (clear glass), and 0% means completely opaque. A 35% VLT tint allows 35% of light to pass through and blocks 65%. Law enforcement use a handheld light meter called a tint meter to measure the darkness of your windows during a traffic stop.

When you have tint installed, the shop applies a film to the inside of the glass. The darkness of that film, combined with the darkness of the factory glass itself, determines the final VLT reading. Some factory glass is slightly tinted, so a 35% VLT film on factory glass may read lower than 35% when measured together. This is why it matters to tell your tint installer that you need to stay legal in Illinois — they will account for the factory glass darkness and choose a film that keeps you within the limit when combined.

Front Windows, Rear Windows, and Windshield Rules

Illinois divides your car into three tint zones, each with different rules. Front side windows — the windows next to the driver and front passenger — must allow at least 35% of light through. This is the strictest requirement because the state wants to may support drivers and passengers are visible to law enforcement and other drivers.

Rear side windows — the windows behind the front doors — can be any darkness, including completely black. Rear windshields also have no darkness limit. This is why many drivers choose to tint only the rear windows if they want maximum privacy.

Your windshield cannot have any tint film below the AS-1 line. The AS-1 line is the manufacturer's marking on the top of the windshield, usually about 4 to 6 inches down from the top edge. You can have a sun visor or sunshade, but any permanent tint film must stay above that line. Windshield tint below the AS-1 line is illegal even if it is very light.

Medical Exemptions for Darker Front Window Tint

If you have a medical condition that makes you sensitive to sunlight, you may be able to get an exemption to use darker tint on your front side windows. Conditions that typically may have access to include lupus, porphyria, xeroderma pigmentosum, polymorphous light eruption, and severe photosensitivity disorder. Your doctor must believe that tint is medically necessary to protect you from harm.

To obtain an exemption, you need a letter from a licensed physician — an MD or DO — stating your diagnosis, explaining why sunlight exposure is harmful to you, and recommending window tint as part of your treatment. The letter should specify how dark the tint needs to be. You then carry this letter in your vehicle. If you are stopped by law enforcement, you show them the letter and your medical documentation. The exemption does not make you immune to a traffic stop, but it provides a legal defense if your tint is darker than the standard 35% limit.

Illinois does not issue a separate medical exemption certificate or sticker. The letter from your doctor is your proof. Keep it accessible — in the glove compartment or with your registration — so you can produce it quickly if asked.

What Happens If Your Tint Is Too Dark

If a police officer measures your front windows and finds they transmit less than 35% of light, you can receive a citation for illegal window tint. This is typically a non-moving violation, meaning it does not add points to your driving record, but you still have to pay a fine. The fine ranges from $100 to $500 depending on the court and the officer's discretion.

You have the right to contest the citation. You can request that the officer's tint meter be calibrated and certified, or you can have your windows measured independently by a professional tint shop. If you can show that your front windows actually meet the 35% standard, the citation can be dismissed. Some drivers have successfully challenged citations by presenting independent measurements or by arguing that the officer's meter was not properly calibrated.

If you receive a citation, you have the option to remove or lighten the tint to comply with the law. Once you do, you can request that the citation be dismissed or reduced, depending on the court's policy. Some courts will waive the fine if you provide proof that you have corrected the violation.

Tint Installation and Choosing a Shop

Window tint is applied by hand at a tint shop. The installer cleans the inside of your windows, cuts the film to fit, and applies it with a squeegee to remove air bubbles. The process usually takes 2 to 4 hours depending on how many windows you are tinting. The cost ranges from $150 to $400 for a full car, though prices vary by shop and location.

When you choose a shop, tell them you need tint that is legal in Illinois — specifically, 35% VLT or lighter on front side windows. A reputable shop will know the law and will not install tint darker than that on your front windows unless you show them a medical exemption letter. Ask the shop what film brand they use and whether they warranty the work. Most shops offer a warranty against peeling, bubbling, or fading for 3 to 5 years.

After installation, avoid rolling down your windows for 24 to 48 hours while the film cures. Do not wash the windows for at least a week. If you notice bubbles or peeling within the warranty period, contact the shop and they will repair or replace the film at no cost.

Frequently Asked Questions

Can I tint my windshield in Illinois?

You can tint the top of your windshield above the AS-1 line — the manufacturer's marking that is usually 4 to 6 inches from the top. Any tint below that line is illegal. Many drivers use a sunshade instead, which is legal and removable.

Do I need to register my tint or get it inspected before I drive?

No. Illinois does not require pre-approval, registration, or inspection of window tint. You can have it installed and drive when ready. However, law enforcement can measure your tint during any traffic stop and cite you if it is too dark.

What if I have a medical condition and need darker tint?

You need a letter from a licensed physician stating your diagnosis, explaining why sunlight is harmful, and recommending tint. Carry this letter in your vehicle. If stopped, show it to the officer. The letter provides a legal defense against a citation for dark front window tint.

Can I tint my rear windows as dark as I want?

Yes. Illinois has no darkness limit for rear side windows or rear windshields. You can tint them completely black if you choose. Only your front side windows are restricted to 35% VLT or lighter.

What should I do if I get a citation for illegal tint?

You can contest it by requesting that the officer's tint meter be certified or by having your windows measured independently. You can also remove or lighten the tint and ask the court to dismiss or reduce the fine. Some courts waive fines if you correct the violation.