Choose the factory headlight system below to see the correct bulb and recommendation path for this 2021 Audi A4.
Choose the factory system installed in this vehicle. Bulb sizes and recommendations change with that selection.
These products were physically tested by BulbFacts, but the tests were not performed in this exact vehicle unless a card explicitly says otherwise.
Low Beam: D5S · High Beam: H11
Low Beam D5S
The DDM Ultra Xenon is the value pick because the 5500K version delivers strong low-beam performance at a much lower price than the major premium brands.
General BulbFacts housing testA matching bulb size identifies fitment; it does not by itself prove optical compatibility or make a conversion a vehicle-specific recommendation.
Support independent testing: BulbFacts may earn a commission from qualifying purchases through these links, at no extra cost to you. Affiliate relationships do not determine test results or recommendations.
These products were physically tested by BulbFacts, but the tests were not performed in this exact vehicle unless a card explicitly says otherwise.
Low Beam: D5S · High Beam: H11
Low Beam D5S
The DDM Ultra Xenon is the value pick because the 5500K version delivers strong low-beam performance at a much lower price than the major premium brands.
General BulbFacts housing testA matching bulb size identifies fitment; it does not by itself prove optical compatibility or make a conversion a vehicle-specific recommendation.
Support independent testing: BulbFacts may earn a commission from qualifying purchases through these links, at no extra cost to you. Affiliate relationships do not determine test results or recommendations.
Available exterior and interior lighting data for this model year.
Fitment, factory-system research, and BulbFacts product tests remain separate evidence. A matching bulb size does not by itself make a conversion a vehicle-specific recommendation.
| Position | Bulb or system | Evidence status |
|---|---|---|
| Low BeamModel: allroad | D5S | Likely fitment |
| High BeamModel: allroad | H11 | Likely fitment |
| Low BeamModel: Quattro | D5S | Likely fitment |
| High BeamModel: Quattro | H11 | Likely fitment |
Fitment note: Verify the installed bulb, connector, housing, and factory system before ordering. A bulb-size match is not automatically a conversion recommendation or proof of vehicle-specific testing.
