What Bulbs Are in an Audi A4?

An Audi A4 typically uses a mix of halogen, xenon (HID), and LED bulbs depending on the model year and trim; common types include H7 or H11 for halogen headlights in older models and fully integrated LED units in newer generations, while interior and signal lighting often rely on W5W, P21W, PY21W, and various LED modules. The exact bulb types vary significantly between B7, B8, B9, and the latest B10 generations, and also depend on whether the car has optional Xenon or Matrix LED headlights.

Contents

Why Bulb Types Vary So Much on the Audi A4
Key Warning Before You Start
Typical Bulb Types by Generation
Common Exterior Bulb Types Across Many A4s
Upgrading Audi A4 Bulbs: Halogen to LED and Beyond
How to Identify Your Audi A4 Generation
Summary

Why Bulb Types Vary So Much on the Audi A4

The Audi A4 has evolved through several generations—B6/B7 (early–mid 2000s), B8 (2008–2015), B9 (2016–2023) and the new B10 (from 2024)—and each step brought more advanced lighting options. Early cars mostly used halogen bulbs, mid‑generation models introduced bi‑xenon and LED daytime running lights (DRL), and the latest models now rely heavily on fully integrated LED and Matrix LED systems where individual “bulbs” are no longer user‑replaceable in the traditional sense. Trim level, country regulations, and optional lighting packages also change the exact bulb types.

Key Warning Before You Start

Bulb types below are typical, not guaranteed. Audi frequently revises part suppliers and specifications even within a single model year. Always confirm against your specific vehicle’s documentation or parts catalog.

How to Confirm the Exact Bulb for Your A4

To avoid fitting the wrong part—or damaging lenses or wiring—owners should verify bulb types using several reliable sources and methods.

The following list outlines practical ways to confirm the correct bulb specification for an Audi A4 before purchase or installation.

Check the owner’s manual: Audi usually provides a bulb chart for exterior and interior lights per model year.

Use the VIN at a dealer: An Audi dealer can look up exact part numbers and bulb types based on your VIN.

Online OEM catalogs: Sites using ETKA data (or region-specific Audi parts portals) let you enter your VIN or model and see part numbers.

Look directly at the existing bulb: Many bulbs are marked (e.g., H7, H11, W5W, P21W, D3S), though some LED modules are only labeled by part number.

Use reputable bulb finder tools: Major bulb manufacturers (Osram, Philips) offer online “vehicle bulb finder” tools that are usually up to date.

Check for retrofit kits: If your car has retrofit LED upgrades, it may no longer use the original bulb types shown in manuals.

By confirming via at least two of these methods, Audi A4 owners can reduce the risk of ordering incorrect bulbs and ensure compatibility with the car’s lighting and monitoring systems.

Typical Bulb Types by Generation

Although there is substantial variation, most Audi A4s fall into widely used patterns for their exterior bulb types. Below is a generation‑by‑generation overview to orient owners before they look up their exact car.

Audi A4 B7 (circa 2004–2008)

The B7 generation bridged the gap between old‑school halogen systems and more advanced xenon options, particularly on higher trims.

The following list summarises the most common bulb types found in B7 Audi A4 models, noting differences between standard halogen and optional xenon setups.

Low beam (halogen models): Often H7

High beam (halogen models): Frequently H7 or H1 depending on market

Optional xenon low/bi-xenon: Typically D2S or D1S HID capsules

Front fog lights: Commonly H11 or H7

Front indicators: PY21W (amber)

Front position/parking lights: W5W (T10 wedge)

Rear brake/tail lights: P21/4W or P21W + separate tail bulb, depending on lamp design

Rear indicators: PY21W

Reverse lamps: P21W or W16W, depending on body style

Rear fog: P21W

Number plate lights: W5W

Interior dome/map lights: Festoon (e.g., 36–42 mm) and W5W wedge in some locations

While there are variations by country and trim, B7 owners will typically be dealing with traditional halogen and a limited number of HID xenon capsules, making most bulb changes DIY‑friendly with basic tools.

Audi A4 B8 (2008–2015, including B8.5 facelift)

The B8 generation introduced the Audi “LED eyebrow” look on many trims and brought bi‑xenon headlights and LED DRLs into the mainstream, especially after the facelift around 2012.

The following list gives an overview of typical bulb types found on B8/B8.5 Audi A4 models, covering both halogen and xenon/LED variants.

Low beam (halogen headlights): Commonly H7

High beam (halogen headlights): H7 or H9 in many markets

Bi-xenon low/high beam: Usually D3S HID capsules

LED daytime running lights: Integrated LED strips/modules (non‑serviceable as individual “bulbs”)

Front fog lights: H11 or H8 depending on bumper and trim

Front indicators: PY21W or LED strip/module on some xenon/LED packages

Front side/parking lights: W5W on halogen units; function often integrated into DRL/LED module on higher trims

Rear brake lights: P21W on halogen rear clusters; LED modules on higher trims and Avant models

Rear tail lights: W5W/P21W or LED, depending on cluster type (sedan vs Avant and options)

Rear indicators: PY21W on most non‑LED clusters

Reverse lights: W16W or P21W depending on body style

Rear fog: P21W or LED in some LED clusters

Number plate lights: W5W or LED modules from factory on some later cars

Interior lights: A mixture of festoon bulbs (31–42 mm), W5W wedges, and small LEDs in ambient lighting areas

Because the B8 generation mixes conventional bulbs with fixed LED modules, owners can still replace many bulbs themselves, but failures in DRLs or LED rear clusters often require replacing the entire lamp or LED module assembly.

Audi A4 B9 (2016–2023)

The B9 moved decisively toward LEDs, with halogen front lamps largely phased out in many markets and full LED or Matrix LED systems becoming widely available.

The following list describes the typical lighting architecture and bulb types or modules used on B9 Audi A4s, taking into account different headlight options.

Base headlights (earlier B9 in some markets): Halogen units with H7 (low) and H15 or H7 (high/DRL) in limited configurations; these became rare over time.

LED headlights: Fully integrated LED modules for low/high beam and DRL—no conventional replaceable “bulb”; entire module/lamp replaced if it fails.

Matrix LED headlights (optional/high trims): Advanced multi‑segment LED modules; again, no traditional bulb replacement.

Front indicators: Usually integrated LED strips or segments within the headlamp, often with dynamic “sweeping” indicators on higher trims.

Front fog/“cornering” function: Often implemented via LED modules within headlamps or bumper units (not user‑replaceable bulbs).

Rear lights (pre‑facelift B9): A mix of LED for tail/position and conventional P21W/PY21W for indicators and reverse in some markets; other trims use almost full LED clusters.

Rear lights (B9 facelift with dynamic indicators): Largely fully LED (tail, brake, indicators, and fog) with some models still using W16W or P21W for reverse lamps.

Number plate lights: LED modules

Interior lighting: Predominantly LED modules (including ambient lighting), not conventional bulbs, especially on higher trims and S line models.

With the B9 generation, most external and internal lighting has shifted to sealed LED modules; while highly reliable, they generally require professional replacement of modules or complete units instead of simple bulb swaps.

Audi A4 B10 / Latest Models (from 2024, including A4 successor lines)

The newest A4‑line models sold in various markets (including successors branded as A5 or the all‑electric A4 e‑tron family, depending on region) rely almost entirely on LED or Matrix LED technology.

The list below summarises the prevailing lighting design of the latest A4‑family models now entering showrooms.

Headlights (all trims in most markets): LED or Matrix LED only; no halogen option.

Low/high beams: Fully integrated LED or Matrix LED modules—no separate bulbs.

Daytime running lights: Programmable LED light signatures built into the headlamp cluster.

Front indicators: Dynamic LED segments.

Rear lights: Fully LED, often with OLED rear light options on higher trims.

Reverse lights: LED segments integrated into the tail‑lamp assembly.

Rear fog lights: LED modules in the rear clusters or lower bumper.

Number plate lights: LED modules.

Interior lighting: Extensive LED ambient and functional lighting; mostly non‑serviceable at bulb level.

On these latest models, traditional bulb replacement is largely obsolete; lighting is treated as modular electronics, with diagnostics and replacement typically handled by authorised workshops.

Common Exterior Bulb Types Across Many A4s

Despite the shift to LEDs, several conventional bulb types recur across multiple Audi A4 generations, especially on older or non‑LED models.

The following list highlights the most widely used conventional bulb types that A4 owners are likely to encounter when working on earlier generations or base trims.

H7: Widely used for low beams and sometimes high beams in halogen headlamp units.

H11 / H8: Common in fog lights and some later halogen headlamp designs.

H1 / H9: Occasionally used for high beams, depending on market and year.

D1S / D2S / D3S: HID xenon capsules used in OEM xenon and bi‑xenon systems on B7 and B8 models.

W5W (T10 wedge): Frequently used for side/parking lights, interior lights, and number plate lights on older cars.

P21W: Common as brake, reverse, or rear fog bulbs on various generations.

P21/4W or P21/5W: Dual‑filament bulbs used for combined tail/brake functions.

PY21W: Amber indicator bulbs for front or rear turn signals.

W16W: Used for reverse or interior lighting in some models.

Festoon bulbs (e.g., 31–42 mm): Common in interior dome, map, and luggage compartment lights in earlier generations.

These bulb types are widely available from major manufacturers like Osram and Philips, making them straightforward replacements for many Audi A4 owners maintaining older models.

Upgrading Audi A4 Bulbs: Halogen to LED and Beyond

With many A4 owners driving older B7 or B8 models, upgrading to brighter or whiter lighting is a frequent modification, but it must be done carefully to remain legal and to avoid dash error messages.

Considerations When Upgrading Halogen Bulbs

Owners of halogen‑equipped A4s often consider upgrading to “plus” halogen bulbs or LED retrofits. Each option carries trade‑offs in brightness, lifespan, legality, and compatibility with Audi’s bulb monitoring systems.

The following list outlines key factors to consider before installing upgraded bulbs on an Audi A4.

Legality: In many regions (including much of Europe), LED retrofit bulbs in halogen headlamp housings may not be road‑legal unless specifically approved (e.g., E‑marked for that application).

Beam pattern: Poorly designed LED retrofits can distort the headlight beam pattern, causing glare and MOT/TÜV/inspection failures.

CAN‑bus compatibility: The A4’s bulb monitoring system may throw warnings if LED retrofits draw too little current; “CAN‑bus compatible” or resistor‑equipped bulbs may be necessary.

Heat and housing limits: High‑output halogen upgrades run hotter and can shorten reflector or lens life if overused.

Colour temperature: OEM xenon and LED systems typically sit around 4300–5000K; very blue bulbs (6000K+) may reduce practical visibility in bad weather.

Warranty and insurance: Modifications to lighting can affect warranty or insurance coverage if they contribute to an accident or electrical fault.

By choosing reputable, vehicle‑specific products and paying attention to local regulations, Audi A4 drivers can achieve better lighting performance without compromising safety or compliance.

How to Identify Your Audi A4 Generation

Knowing whether you drive a B7, B8, B9 or newer A4 is the first step to narrowing down likely bulb types, and it can usually be done by model year and styling cues.

The following list presents a simple reference to help owners identify their A4 generation before looking up bulb specifications.

B7 (approx. 2004–2008): Shares body shape with late B6 but with sharper front bumper and grille; older interior design with simpler MMI or double‑DIN radios.

B8 (2008–2015): Larger body, more angular lights, and the classic early LED “eyebrow” DRL on many trims; updated cabin with central MMI dial.

B9 (2016–2023): Crisper, more horizontal headlamps; more pronounced shoulder line; virtual cockpit available; LED headlights common even on lower trims.

B10 / latest generation (from 2024): Even sharper, more aggressive LED signatures, large grille variations, and heavily digital interiors with extensive screens; often marketed slightly differently depending on market.

Once owners know their generation, they can combine that with trim level and headlight style (halogen, xenon, LED, Matrix LED) to pinpoint the correct bulb or module information with much greater accuracy.

Summary

An Audi A4 can use a wide range of bulb types—H7, H11, D1S/D3S xenon capsules, W5W, P21W, PY21W, and multiple festoon sizes in older models, shifting almost entirely to LED and Matrix LED modules in B9 and latest‑generation cars. The exact lighting specification depends on model year, generation, and options such as xenon or Matrix LED headlights. Because Audi increasingly uses integrated LED modules rather than traditional replaceable bulbs, especially from the B9 onward, owners should always confirm bulb types via the owner’s manual, VIN‑based parts lookups, or reputable bulb databases before buying replacements or upgrades.

What type of headlights does Audi use?

matrix LED headlights
Finally, matrix LED headlights are at the top of the Audi lighting technology food chain, providing illumination that’s both intuitive and proactive. The goal is to light the way for the driver without blinding oncoming traffic.

What bulbs are in the Audi A4?

H7 (499)
H4 (472)
H11.
H1 (448)
HB3 (9005)
HB4 (9006)
H8/H11/H16.
HIR2.

How much does it cost to replace a headlight bulb in an Audi A4?

Replacing an Audi A4 headlight bulb can cost anywhere from approximately $25 to over $250 per bulb, depending on the type of bulb and whether you do it yourself or have a shop do it. DIY costs for just the bulb range from roughly $20 to $150 or more, while professional installation adds significant labor costs.
DIY replacement

Parts cost: Expect to pay anywhere from $20 for a basic halogen bulb to over $150 for an HID bulb.
Tools: Basic tools like a Torx and Phillips head screwdriver may be needed.
Difficulty: The difficulty varies by model year. Some A4s allow for easy access, while others may require removing the inner fender well, adding to the complexity.

You can watch this video to learn how to replace the headlight bulb on an Audi A4: 57sHaynes ManualsYouTube · Jan 9, 2024
Professional replacement

Shop/Dealer price: You can expect to pay between $215 and $265 or more for professional replacement of a single low beam bulb, which includes both parts and labor.
Labor costs: Labor is a significant part of the total cost, especially for newer models with complex designs.

This video shows how to replace a headlight bulb on an Audi A4 from 2009 to 2016: 1mSmackey’s GarageYouTube · Oct 1, 2024
Factors affecting the total cost

Bulb type: HID bulbs are significantly more expensive than halogen bulbs.
Labor vs. DIY: Performing the replacement yourself will be much cheaper than paying for professional installation.
Vehicle model and year: The design and accessibility of the headlight assembly can vary by model year, affecting labor time and cost.

Are H11 and H7 bulbs the same?

No, H7 and H11 bulbs are not the same and cannot be used interchangeably because they have different base designs, socket types, and dimensions. The primary differences are their base configuration and the type of application they are designed for; H7 bulbs are often used for both low and high beams, while H11 bulbs are typically for low beams or fog lights.
Key differences between H7 and H11 bulbs

Feature	H7	H11
Base/Socket Design	PX26d base with two bare prongs	PGJ19-2 base with two encased prongs
Application	Low and high beams	Low beams and fog lights
Dimensions	Larger diameter (~26 mm)	Smaller diameter (~19 mm)
Interchangeability	Not interchangeable with H11	Not interchangeable with H7

Check your owner’s manual: This is the most reliable source for the correct bulb type for your vehicle.
Examine the existing bulb: Take out the old bulb and look for the bulb number printed on its base.
Use an online bulb finder: Many automotive parts websites have tools that can look up the correct bulb for your specific vehicle.