LED Bulb Base Guide

As one of the most energy efficient lighting options that has many advantages over other lighting, LED bulbs quickly became highly popular when they were first released to the public and are now widely used by everyone. However, being differ in shapes, bases, and purposes, there are tons of led light bulbs to choose from, which is great but also frustrating.

Then, as the part of a light bulb that connects with the fitting and holds it in place, the base type is one of the things you need to consider when purchasing any new led bulb. Or the bulb will not work if you choose the wrong base type for the application. But what are the different base types of LED light bulbs? Setting all those charts out below and then describe each type of bulb base, here's your LED light bulb base guide to help you locate the correct bulb.

Lighting Tip: in some older light bulb catalogs, bases are referred to as "caps."

OUTLINE OF LED BULB BASE TYPES:
Edison Screw Bases
Twist and Lock Bases
Bayonet Bases
BI Pin Bases

Edison Screw Bases

LED light bulb base types are typically measured by type and diameter in millimeters, and among them, the most common bases everyone is familiar with start with an E, signifying "Edison" type screw bases. The number after the E represents the diameter of the base in millimeters.

When it comes to LED light bulbs, there are so many screw bases of them to choose from. Here are some examples of Edison bases and their more commonly-known names, from the common e12 bulb to e26 bulb, just click or tap on the item image to view matching bulbs from our catalog.

E12 LED Bulb - Candelabra Bulbs

Having a diameter of 12 mm, these types of light bulbs are considered smaller. They are generally used for night light bulbs but can also be found in some decorative bulbs used over the in a chandelier.

**Technical Details Comparison of LOHAS E12 Light Bulbs**
	e12 smart bulb	e12 color changing light bulb	e12 filament vintage light bulb	e12 filament vintage light bulb	e12 decorative cylindrical bulb
Price	$26.99/2 Pack	$29.99/2 Pack	$22.99/6 Pack	$29.99/6 Pack	$18.99/3 Pack
Lumen	450LM	810LM	400LM	600LM	1100LM
Watt (Replacement Watt)	5W (40W Equivalent)	9W (60W Equivalent)	4W (40W Equivalent)	6W (60W Equivalent)	12W (100W Equivalent)
Light Color	RGB & Cool White	RGB & Tunable White	Warm White	Warm White	Warm White
Color Temperature	2700K-6000K	2700K-9000K	2700K	2700K	2700K
Shape	Candle	A19	ST48 Beam angle: 330°	Candle	Candle
Key Functions	Controlled by Voice and APP	Controlled by Voice and APP	Decoration	Decoration	Decoration
Dimmable	√	√	√	×	×

E26 LED Bulb - Medium Bulb

E26 base is the most common light bulb base that you can buy and is used in LED light bulbs. Most of the e26 light bulbs that you buy in stores or online are going to have this kind of base, like color changing light bulb, dusk to dawn light, and yellow led bulbs etc..

**Technical Details Comparison of LOHAS E26 LED Bulbs**
	e26 smart bulb	e26 dusk to dawn light bulb	e26 yellow led bulb	e26 smart retrofit downlight	e26 led daylight bulb
Price	$21.99/2 Pack	$25.99/4 Pack	$19.99/4 Pack	$25.99/Pack	$29.99/4 Pack
Lumen	450LM	500LM	450LM	680LM	2500LM
Watt (Replacement Watt)	8W (60W Equivalent)	6W (40W Equivalent)	5W (40W Equivalent)	10W (65W Equivalent)	23W (150 - 200W Equivalent)
Light Color	RGB & Cool White	Daylight White	Orange Yellow	RGB & Tunable White	Daylight White
Color Temperature	2700K-6000K	5000K	2000K	2000K-9000K	50000K
Shape	A19	A19	A15	Round	Candle
Key Functions	Controlled by Voice and APP	Auto Turn ON or OFF	Provide sufficient illumination without attracting bugs	Decoration Controlled by Voice and APP	Light comes on instantly when turned on
Dimmable	√	×	×	√	×

Other Edison bases and their more commonly-known names:

E39 - Mogul
E17 - Intermediate
E11 - Mini Candelabra
E10 - Miniature / Mini Screw
E5 - Midget

NOTE: Most Edison base bulbs have a single contact at the center of the base. Some special bases are double contact, and their base adds a "d" at the end, such as E26d.

Twist and Lock Bases

The twist and lock socket and base system like gu24, gu10 or mr16/gu5.3 is designed to replace the Edison socket and base in energy efficient lighting fixtures to match the newest ENERGY STAR requirements. For instance, the fixture that use gu24 bulb is designed to avoid backward compatibility with screw base bulbs, guaranteeing 5 higher energy efficiency.

Also, some of the most popular twist and lock bases are GU5.3 and GU10 which are found with MR16 LED bulbs. The GU5.3 base just plugs into the socket while G U10 bulbs, as well as GU24 base LED bulbs, twist and lock into place.

Bayonet Bases

Bayonet base LED bulbs have notches on the side of the base which are used to lock the bulb into place. There are generally two different kinds of bayonet base bulbs, single contact (SC) or double contact (DC) like b22 and b15, which denotes if there are one or two contact points on the end of the bulb for electrical connectivity.

BI Pin Bases

Bi-pin bases are denoted with a "G" followed by a number which indicates the width of the space between the pins. And the bi pin-based LEDs have small plastic bases with two or four pins and are designed to be used with separate ballasts mounted in fixtures, g9 led bulb for instance. There are also instances when there are letters following the number to indicate how many pins the bulbs has. "S" stands for single-pin, "D" stands for double-pin, "T" for triple, and "Q" for quadruple.

Now, you may know that all bulb bases are defined by a code of numbers that include both letters and numbers. These aren't there for show, they mean something, and play an important role in choosing the right led bulb. So, in an effort to try and simplify the light bulb puzzle, we set this post here to put together a series of custom light bulb charts that illustrates base types. Share it with your friend if you find it helpful.