What Is the Rear Window of a Car Called? (Backlight, Back Glass)

The rear window of a car is most often just called the rear window or back glass. Its formal name in manufacturer parts catalogs and repair manuals is the backlight, and rear windshield is the popular but less precise label, according to CarXplorer’s auto-glass terminology guide. The glass is usually tempered, unlike the laminated front windshield, and it often carries a printed defroster grid. This guide covers every name, why the name changes by body style, how the glass is made and marked, what the lines and black dots are, and what to do when it breaks.

What’s the Rear Window of a Car?

The rear window is the pane of glass at the back of a vehicle that gives the driver a view of the road behind and closes the cabin against weather. It has several names, and which one you hear depends on who is talking. This glossary follows CarXplorer’s list of the common names:

Name	Where you hear it	Notes
Rear window	Everyday speech	The most common and widely understood term
Back glass	Auto repair and insurance work	Common among glass technicians and adjusters
Backlight	Parts catalogs, repair manuals, engineering	The formal technical term for the rear glass
Rear windshield	Everyday speech	Popular, but a loose use of “windshield”
Rear windscreen	British English	The British equivalent of rear windshield

If you are searching a parts catalog or ordering glass, look for the backlight entry for your exact vehicle. In conversation, rear window or back glass will be understood by everyone from drivers to mechanics.

Why Does the Rear Window Have Different Names?

Part of the confusion is body style. CarXplorer notes that the glass on a sedan or coupe is the rear window, while on a hatchback or SUV the glass sits in the rear door and is called hatch glass, a term that can include the frame and the wiper. The glass does the same job in both cases, but on a hatchback it lifts with the door.

The rest comes from the word windshield. The front glass is called a windshield because its job is to shield occupants from wind, rain and debris, and it is made of laminated glass. Glass purists therefore say rear windshield is a misnomer, because the rear glass is built differently and does not face those forces head-on. In British English the front glass is a windscreen, which is why you also meet rear windscreen.

Backlight is the term used for the rear glass in OEM parts catalogs and repair manuals. Source: CarXplorer, What Is a Car’s Rear Window Called.

What’s the Purpose of the Rear Window?

MS Glass Outlet, an auto glass shop, lists four jobs for rear windows: protecting occupants from flying debris, giving a direct view of the road and any obstruction behind the car, helping prevent occupants from being ejected in a crash, and supporting the vehicle frame. CarXplorer adds that modern rear windows are bonded to the body and contribute to its rigidity, including in a rollover.

Federal glazing rules describe the same goals. Federal Motor Vehicle Safety Standard 205 says its purpose is to reduce injuries from impact to glazing surfaces, to ensure the necessary degree of transparency for driver visibility, and to minimize the chance of occupants being thrown through windows in collisions. It applies to passenger cars, multipurpose passenger vehicles, trucks, buses and motorcycles, among other vehicles.

How Is the Rear Window Made?

Most rear windows are tempered glass, which MS Glass Outlet describes as ordinary glass treated with heat, pressure or chemicals to strengthen it. When it breaks, tempered glass usually shatters into many small pieces with somewhat rounded edges instead of sharp shards. The front windshield is different: it is laminated, two sheets bonded with a layer of polyvinyl butyral that holds the pieces in place.

Look for the marks. Under FMVSS 205, a glass maker certifies each piece by adding the letters DOT and a manufacturer code that NHTSA assigns, next to the markings required by the ANSI/SAE Z26.1 glazing standard. ScienceABC explains the AS ratings you may see beside them: AS1 is laminated glass allowed for the windshield, AS2 is tempered glass cleared for side and rear windows, and AS3 is the darker privacy-tinted glass used behind the front seats.

Features of the Rear Window

A modern rear window carries more than glass. The common features are:

• Defroster grid: the thin horizontal lines. They are not wires buried in the glass. ScienceABC describes a grid of silver-bearing conductive paste silk-screened on the inside surface and baked on, which heats up when current passes through it.
• Antenna: in many cars the same lines double as a radio antenna. ScienceABC says the grid is often split into an upper and lower half that can pick up FM, with a separate flat element for AM, and filters keep the heating current out of the radio.
• Black band and dots (frit): a ceramic enamel baked on at about 600 to 700 degrees C. It hides the urethane adhesive that bonds the glass to the body and shields it from ultraviolet light, which degrades urethane.
• Wiper: hatch glass on SUVs and hatchbacks often comes with a wiper, per CarXplorer.
• High-mounted stop lamp: the third brake light, mounted high at the rear. FMVSS 108 says that if the lamp is mounted below the rear window, its lens may be no more than 77 mm (3 in) below the lower edge of the rear glazing on a passenger car other than a convertible.

Types of Rear Windows by Vehicle

Body style decides how the rear glass is built into the car:

• Sedan or coupe rear window: a fixed pane in the body behind the trunk lid; it does not open.
• Hatchback or SUV hatch glass: glass set in the rear door that lifts as a unit, often with a frame and wiper, per CarXplorer.
• Other body styles: pickups, vans and convertibles vary by model, so use the backlight entry in your own vehicle’s parts catalog or owner’s manual for the exact name.

How Are Rear Windows Installed?

MS Glass Outlet describes the replacement sequence. The shop orders a panel matching your original glass, removes broken glass from the frame and the cabin, and prepares the frame. It then fits the new glass and replaces damaged weather-stripping if needed. If the original had a defroster, a new grid is part of the replacement and is connected to the system tabs. Finally, the adhesive is allowed to cure and the defroster is tested before the car leaves.

Replacement glass must still meet the federal standard. FMVSS 205 says glazing intended as aftermarket replacement has to meet the standard or the requirements that applied to the glass being replaced, so look for the DOT mark described above. For a step-by-step view of the job, see our guide to replacing car window glass, and for budgeting, our breakdown of what it costs to replace car window glass.

Common Problems with Rear Windows

MS Glass Outlet lists three common causes of rear window damage: thermal stress when glass heats up or cools down too quickly, impact from debris such as stones or baseballs, and collisions. Tempered glass generally needs a harder hit to break than laminated glass, but it does not tolerate chips well.

• Cracks and chips: MS Glass Outlet says even a small crack or chip in tempered glass can compromise the whole panel, so replacement is usually the only option, and some damaged panels have shattered spontaneously from road vibration. Our guide on whether car glass can break on its own covers the causes.
• Defroster not working: a broken line in the grid can leave part of the glass fogged. Because the lines are a thin printed layer on the inside surface, avoid razor blades and abrasive pads on that side. A small break can sometimes be bridged with conductive paint, as in the repair kit above; a cracked panel cannot.
• Weather-stripping wear: damaged seals are replaced during glass service, as the replacement steps above show. Our guide to replacing car window seals shows what that involves.

Table: Rear Window Features by Vehicle Type

Body style	Common names	Typical glass	What to expect
Sedan or coupe	Rear window, back glass, backlight	Tempered (usually)	Fixed pane; defroster grid common
Hatchback or SUV	Hatch glass, rear windshield (colloquial)	Tempered (usually)	Lifts with the rear door; frame and wiper often included
Any vehicle	Backlight (parts catalog)	Check the DOT and AS marks	Exact part depends on trim, tint and grid

Rear glass is usually tempered, but trim, tint and options vary, so confirm the glass type from the markings on the glass or in the parts catalog before ordering.

How to Maintain Your Rear Window

• Clean it gently: use a soft cloth on the inside so you do not scratch the printed grid. Our guide to cleaning the inside of car windows without streaks has a streak-free method.
• Test the defroster: run it in cool weather and check that the whole grid warms and the fog clears evenly; a stripe that stays foggy points to a broken line. If the glass fogs often, see how to defog car windows.
• Let ice melt gradually: MS Glass Outlet says glass that heats or cools too quickly can break from thermal stress, so let the defroster work instead of pouring hot water on frozen glass.
• Do not drive on damage: replace a chipped or cracked rear window rather than waiting, for the reasons above.

Rear Window vs. Front Windshield

Feature	Front windshield	Rear window
Glass type	Laminated: two sheets bonded with a plastic layer	Tempered (usually)
When it breaks	Cracks and the layer holds the pieces	Shatters into many small, somewhat rounded pieces
Small chip or crack	Often repairable	Replacement is usually the only option
How it is defrosted	Warm air from dashboard vents	Electric grid on the glass
Name origin	Shields occupants from wind and debris	Called rear window or backlight; rear windshield is a loose term

Aftermarket Rear Windows and Modifications

If you replace or modify the rear glass, the glass still has to comply with the federal standard. Under FMVSS 205, aftermarket replacement glazing must meet the standard or the requirements that applied to the glazing being replaced, and a person who cuts a section of glazing for use in a vehicle must mark and certify it. In practice, buy glass that carries the DOT mark and a manufacturer code.

Tint film is the most common modification. Rules differ by state, so read our guide to the legal tint for car windows and check your state’s current limits before you apply any film. Adding or moving a third brake light is also regulated: FMVSS 108 says an interior-mounted high-mounted stop lamp must minimize reflections on the rear window glazing that the driver could see directly or in the mirror.

Safety and Legal Considerations

Federal standards set the baseline. FMVSS 205 requires glazing in motor vehicles to conform to ANSI/SAE Z26.1 and sets certification and marking rules; FMVSS 108 covers lamps, including the high-mounted stop lamp. You can read both texts on the eCFR: 49 CFR 571.205 on glazing materials and 49 CFR 571.108 on lamps. Tint limits, inspection rules and equipment rules for cracked glass vary by state, so check your state before you drive or modify. This is general information, not legal advice.

Why the Rear Window Matters

The rear window shows what is behind you, keeps weather and debris out, helps stiffen the body, and its grid keeps the view clear in cold or humid weather.

Wrapping It Up

Call it the rear window or back glass in conversation, and look for backlight in a parts catalog. The glass is usually tempered, carries DOT and AS marks, and often hosts a printed defroster grid, an antenna and a frit band. Replace chipped or cracked rear glass promptly, buy replacement glass that meets FMVSS 205, and check your state’s tint rules before you change anything.

This guide does not cover replacement prices or state-by-state tint percentages; use the linked guides or ask a glass shop for an estimate on your exact vehicle.

Rear Window FAQs

What’s the difference between a rear window and a rear windshield?

A rear window is the usual name for the glass at the back of a sedan or coupe, while hatch glass is the glass in the rear door of a hatchback or SUV. Many people say rear windshield for either one, but the term windshield describes the front glass whose job is to shield occupants from wind, so rear window or back glass is the safer name.

Can I replace my rear window myself?

It is possible to buy glass and follow a guide, but the job is more involved than it looks. The old glass pieces must be cleared from the frame and cabin, the new glass bonded with adhesive, damaged weather-stripping replaced if needed, and the defroster grid connected and tested. Many owners hand it to a glass shop.

Why does my rear window have wires in it?

Those lines are the defroster grid. Per ScienceABC, they are usually not wires buried in the glass but a silver-bearing conductive paste printed on the inside surface and baked on. When you switch the defroster on, current runs through the lines and their electrical resistance warms the glass enough to clear fog, frost and thin ice.

Is it legal to tint my rear window?

Tint rules are set state by state and differ for the rear window, so check your state’s current limits before applying film. Our guide to the legal tint for car windows explains what to look up. This is general information, not legal advice.

What should I do if my rear window cracks?

Have it inspected promptly. A shop that supplies rear window replacement says even a small crack or chip in tempered glass can weaken the whole panel, and that damaged panels have been known to shatter on the road from vibration alone. Do not keep driving with a cracked rear window if you can avoid it.

What is the third brake light above the rear window called?

It is the center high-mounted stop lamp, often shortened to CHMSL. Federal lighting standard FMVSS 108 defines a high-mounted stop lamp as a lamp mounted high and possibly forward of the tail, stop and rear turn signal lamps, intended to give a steady stop warning through intervening vehicles to following drivers.