Are H7 and H11 the same bulb?

No. H7 and H11 are different automotive headlight bulb types with distinct bases, connectors, and mounting systems, so they are not interchangeable. Both are single-beam 12V halogen categories often used for low or high beams (and fog lights in the case of H11), but their physical fit, electrical connectors, and optical geometry are different. Drivers frequently confuse them because their wattage is similar and they appear in similar applications; however, using the wrong one won’t fit and, if forced, can damage the housing or produce unsafe beam patterns.

What H7 and H11 designations mean

“H7” and “H11” are standardized automotive light-source types defined under ECE Regulation 37 (globally) and recognized by SAE/DOT (North America). Each code specifies base shape, keying, filament position, electrical characteristics, and mounting, which together ensure the correct mechanical fit and optical focus in a properly designed lamp.

H7 at a glance

H7 is a single-filament halogen bulb widely used for low or high beams, particularly in many European and Asian vehicles. It typically operates at 12V 55W, produces about 1500 lumens (at 13.2V per ECE spec), and uses a PX26d metal base. Electrical connection is via two exposed spade tabs, and the bulb is usually retained with a spring clip or adapter ring.

H11 at a glance

H11 is also a single-filament halogen bulb, commonly fitted for low beams and front fog lamps. It typically operates at 12V 55W, produces about 1350 lumens (at 13.2V per ECE spec), and uses a PGJ19-2 plastic, keyed base with an O-ring seal. It connects through a molded, weather-sealed plug and twist-locks into the lamp housing.

Key differences between H7 and H11

The differences below explain why an H7 cannot replace an H11 (or vice versa) without modification—and why such modification isn’t advisable.

• Base and socket: H7 uses a PX26d metal base; H11 uses a PGJ19-2 plastic, keyed base with an O-ring.
• Connector style: H7 has two exposed spade terminals; H11 has a sealed plastic plug with a locking tab.
• Mounting method: H7 is typically held by a spring clip or adapter; H11 twist-locks a quarter turn into the housing.
• Filament position: They’re set differently relative to the base, which is critical for beam focus and cutoff.
• Typical application: H7 is common for low/high beams; H11 is common for low beams and fog lamps.
• Luminous output: H7 is about 1500 lm; H11 is about 1350 lm (both at standardized test voltage).
• Sealing: H11 incorporates an O-ring for moisture sealing; H7 relies on the lamp’s dust cap and clip.
• Physical dimensions: The shapes and keyways differ, preventing correct seating if mismatched.

Taken together, these differences mean the bulbs are engineered for different sockets and optics; even if you could force a fit with adapters, the beam pattern and reliability would be compromised.

Can you swap H7 and H11?

No—there is no direct, safe interchange between H7 and H11. Adapters or “universal” conversions might make a physical connection, but they typically misplace the light source in the reflector/projector, causing glare, poor road illumination, and potential damage or legal issues.

1. Improper focus: The light source won’t sit at the designed focal point, degrading beam pattern and cutoff.
2. Electrical mismatch: Connectors and harness seals don’t mate correctly, risking corrosion or intermittent contact.
3. Mechanical stress: Forcing fitment can break retaining clips, warp sockets, or compromise dust/moisture seals.
4. Regulatory risk: A mismatched bulb type can violate road-legal standards and fail inspections.

If your vehicle specifies H7, use H7; if it specifies H11, use H11. This preserves optical performance, safety, and compliance.

Related bulb families and look-alikes

Some bulb types are often mentioned alongside H7 and H11. Knowing how they relate can prevent costly mistakes.

• H8/H9/H11 family: These share similar keyed plastic bases but differ in wattage, tabs, and filaments; some are modifiable with care, but only use what your vehicle and local regulations allow.
• H11B/H11C: Variants (common in some Korean vehicles) with different tab and connector geometry; they are not the same as standard H11 (PGJ19-2).
• 9005/9006 (HB3/HB4): North American types sometimes used in similar applications; not the same as H11 and not directly interchangeable without proper housings.
• H4/H15: Multi-function bulbs that combine beams or DRL with high beam; not substitutes for H7 or H11.

Even when bulbs seem similar, the correct code on your lamp or in your manual is the one to follow—small geometric differences matter a lot in lighting performance.

Notes on LED “upgrades” and legality

LED replacement bulbs marketed as H7 or H11 must match the base and replicate the filament position to maintain beam focus. Legal status varies by region: in many countries and U.S. states, generic LED retrofits for halogen headlamps are not road-legal unless specifically approved for your vehicle model. Some EU markets now permit certain brand/model-specific H7/H11 LED retrofits with official approvals. Always check local laws and choose products with vehicle-specific certification where applicable.

Buying and replacement tips

Following best practices will help ensure safe, effective lighting and compliance.

• Confirm fitment in your owner’s manual or a trusted parts catalog; match the exact bulb code (H7 vs H11).
• Choose reputable brands that meet ECE/SAE standards; avoid over-wattage bulbs that can overheat housings.
• If considering LED retrofits, verify legal approval for your specific vehicle and market before purchase.
• Replace bulbs in pairs to maintain color and brightness consistency across both lamps.
• Handle glass capsules with clean gloves; oils can shorten bulb life.
• After installation, check headlamp aim and, for H11, ensure the O-ring seats properly to keep moisture out.

These steps protect your vehicle’s lighting performance and help you stay on the right side of safety and regulation.

Summary

H7 and H11 are not the same bulb and are not interchangeable. They differ in bases, connectors, mounting methods, and optical geometry. Use the bulb type specified for your vehicle, and approach any LED “upgrade” with attention to legal approvals and proper beam performance.

What bulb is interchangeable with H7?

Automotive Bulb Chart – Headlights Bulb Cross-Reference

Bulb	Same As	Type
HIR2	9006, 9012, HB4	Halogen
H3	64146BC	Halogen
H4	HB2, 9003, 9003EB, 9003XV, 9003CB, 9003SU, 9003ST	Halogen
H7	64210, H7EB, H7XV, H7ST, H7CB, H7SU	Halogen

Is H11 high or low beam?

An H11 bulb is primarily a low beam and fog light bulb, not a high beam bulb. H11 bulbs provide a focused beam pattern for visibility without dazzling oncoming drivers. While H11 bulbs are not designed for high-beam sockets, some vehicles may use H11 bulbs for both low and high beams, though high-beam specific bulbs like the 9005 (HB3) or H9 offer higher brightness for high-beam use.
 
Key characteristics of H11 bulbs: 

• Purpose: Low-beam headlights and fog lights.
• Beam Pattern: Creates a wide, balanced beam for improved visibility.
• Brightness: Produces around 1350-1450 lumens (for halogen).
• Wattage (Halogen): Typically 55 watts.

Why H11s are for low beams:

• Their design provides a focused, controlled beam to avoid blinding other drivers. 
• They are often used in conjunction with a different, brighter bulb for high beams. 

High beam alternatives:

• For high beams, bulbs like the 9005 (HB3) or H9 offer higher brightness levels. 
• While H11s are not high beams, some vehicles can be equipped with H11 bulbs for both functions, so always check your vehicle’s manual. 

Can I replace a H7 bulb with an H11?

No, you cannot use an H7 bulb instead of an H11 bulb, or vice versa, without modifications. They have different base designs, connectors, and socket sizes, making them incompatible. 
Here’s why:

• Different Connectors: H11 bulbs have a two-pronged, enclosed connector, while H7 bulbs have two exposed prongs similar to a household plug. 
• Different Bases: The base or cap of the bulb, which connects to the socket, also differs between H7 and H11. 
• Socket Size and Shape: The overall size and shape of the bulbs are different, with H7 being slightly larger in diameter. 
• Mounting Mechanism: H7 bulbs often use a twist-lock mechanism, while H11 bulbs are typically plug-and-play. 
• Beam Alignment: Even if you could force one bulb into the other’s socket, the beam alignment would likely be incorrect, affecting light distribution and visibility. 

In essence, the physical differences prevent direct interchangeability, even if the bulbs have similar power ratings. 
This video demonstrates how to convert H11 bulbs to H7 bulbs: 55s4x4TruckLEDs.comYouTube · Feb 10, 2018

What bulb can I use instead of H11?

The H11 bulb is physically compatible with H8, H9, and L-shaped H16 bulbs, as they share the same base and connector. However, they may differ in wattage, typically with H8 and H11 at 55W for low beams or fog lights and H9 at 65W for high beams. It is not interchangeable with the 9006 (HB4) bulb, despite both being used for low beams and fog lights, due to their different sizes and connections.
 
Equivalent Bulbs (Physical Compatibility):

• H8/H9/H16: . Opens in new tabThese bulbs share the same physical design and locking tabs, making them direct fits in an H11 socket. 
• LED Equivalents: . Opens in new tabUniversal H11 LED bulbs are designed to be a direct, plug-and-play replacement for the halogen H8, H9, and H11. 

Non-Equivalent Bulbs (Not Interchangeable):

• 9006/HB4: Do not use a 9006 or HB4 bulb as an H11 replacement, as their physical size and connector are different. 
• 9005/HB3: Do not use a 9005 or HB3 bulb as an H11 replacement. 

Key Considerations When Choosing an Equivalent:

• Wattage and Intended Use: . Opens in new tabCheck the wattage of the replacement bulb. H11 bulbs are usually 55W for low beams or fog lights, while H9 bulbs are 65W for high beams. 
• LED Replacement: . Opens in new tabIf you are switching to LED, ensure the bulb is specifically designed to fit an H11 socket or is a universal model for H8/H9/H11. 
• Vehicle Specifications: . Opens in new tabAlways confirm your vehicle’s specific bulb requirements to ensure compatibility and proper performance.