H11b vs H11 Headlight Bulbs | What’s The Difference?

We review H11b vs H11 headlight bulbs, these two bulbs have similar naming schemes, which is why people think that they are interchangeable. However, that is not the case and there are other differences in terms of the mounting and performance of these bulbs.

The main difference between H11b vs H11 bulbs is their mounting hardware. Besides that there are also some differences in the wiring as well.

If you are unsure which bulb to use on your car, allow us to help. We have been working in the auto industry for over a decade and can help you make a better decision when it comes to headlight bulbs.

Keep reading for more information on H11 and H11b headlight bulbs.

Enclosed connection plug that holds wires in placeExposed connection plug similar to regular electrical plugs
270 hour filament life930 hour filament life
Meant to be used as fog light or in similar configurationsMeant to be used as a low beam headlight bulb
Compatible with various other headlight bulb socketsNot compatible with any other headlight bulb socket
Return wire is placed next to the widest tab i.e at the bottom of the ringReturn wire is placed opposite the widest tab i.e at the top of the ring
Installation involves plugging the headlight bulb into the socketInstallation involves twisting the headlight bulb into the socket
Used by almost all car manufacturersOnly used by a few car manufacturers, such as Hyundai and Kia
Image showing H11b vs H11 differences

H11B vs H11 Bulb – Comparison

Connection plug

The first and most obvious difference between H11 and H11b headlight bulbs is their connection plugs. H11b headlight bulbs have an exposed connection plug which resembles regular electrical plugs used by household appliances. H11 bulbs on the other hand, have an enclosed connection plug that holds the wires in place.

Filament life

Another functional difference between H11 and H11b headlight bulbs is the filament life or lifespan. Specifically, H11 bulbs have a filament life of around 270 hours. H11b headlight bulbs on the other hand, have a filament life of around 930 hours which is over three times as much as H11 bulbs.

Beam type

H11 headlight bulbs are commonly used as fog lights or other similar lights on the front of your car. H11b headlight bulbs are meant to be used as low beam headlights. It is this difference in use case that makes these two headlight bulbs non-interchangeable.


H11 headlight bulbs are compatible with a few other headlight bulb sockets, but not with H11b sockets. In fact, H11b headlight bulb sockets are not compatible with any other type of headlight bulb socket.


In H11 headlight bulbs, the return wire is placed next to the widest tab which is at the bottom of the ring. In H11b headlight bulbs, the return wire is placed opposite the widest tab which is located at the top of the ring. If you were to try and use these headlights in place of one another, by using certain modifications, the wire would drop down over the bulb and cause a shadow to form in your line of sight, thus reducing performance and efficacy.

Installation process

The installation process for H11 bulbs involves plugging them into the socket as you would do with a regular household appliance. As for H11b headlight bulbs, the installation requires that you twist the bulb into the socket. This is another reason why the two are not interchangeable.

Industry adoption

Between H11 and H11b headlight bulbs, H11 bulbs are by far the more common of the two. They are used by almost all auto manufacturers in a wide variety of vehicles. H11b headlight bulbs however, are less common and only used by a few manufacturers such as Hyundai and Kia.


So to sum up, H11 and H11b headlight bulbs are non interchangeable. H11b bulbs have significantly better lifespan, while H11 bulbs are more commonly found on a wider variety of vehicles. The two have completely different installation processes, and the connection plugs are totally unalike. Moreover, the wiring of each is also completely opposite and does not work with the other’s sockets.

For most cases, you will probably require a set of H11 bulbs. If you drive a Hyundai or Kia vehicle, you may need an H11b headlight bulb.

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Hi, I'm Graeme, the author and owner of HeadlightReviews.com. Before I started this hobby site, I used to work alongside my 'Pops', helping out as he worked as a mechanic for over 50 years. Twenty-five of those he was running his own Auto Electrician & Body Shop, where I fell in love with vehicle lighting. I've taken all our experience online (that's not his gig)… so it’s safe to say there are very few people on the internet who can match our expertise and deep understanding of vehicle mechanics, repairs, parts, and especially headlights. If you've got a bulb question, contact me here, and read more about me and headlightreviews.com here.

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