What Is The Difference Between C7 & C9 Lights?

Whether you’re decorating your Christmas tree and home for the holidays, trying to brighten up your deck, patio, or backyard, or planning a special event or party, LED lights and strings are an incredible solution for almost all of your needs! The C7 and C9 LED style bulbs are some of the most recognizable and popular bulbs on the market, you may even know them as the “traditional” LED Christmas lights. These styles of bulbs are extremely versatile, capable of being used indoors and out, and are also longer lasting than traditional incandescents without raising your energy bill.

What Is The Difference Between C7 and C9 Lights?

So if both of these types of lights are versatile and popular, how does one choose which light to go with for your next lighting project? Well there are only a few slight differences between the two styles of bulbs with the main difference being size. C9 LED bulbs measure 1 1/4″ inches in diameter and 2 1/2″ inches tall (C9– retrofit bulbs measure 2 1/4″ x 1 1/8″ and contain  3 LEDs), while C7 LED bulbs measure 1 inch in diameter and 1 1/2″ inches tall (C7 retrofit bulbs measure 1 7/16” x 7/8” and contain 2 LEDs). They both normally can be found in single mold strings or retrofit replacement bulbs and socket wire, with the more popular choice of the being the retrofit bulbs because of their flexibility, low power draw and brightness. Using socket wire and retrofit bulbs gives you more flexibility when faced with odd measurements for example on your roof line. When using C7 or C9 socket wire you have the option to custom cut to length. Comparatively, when using the single mold C7 or C9 strings, if you have access wire you must find a way to hide it or incorporate it into your display.

C7 LED Lights

The smaller of the two bulbs, yet is not to be underestimated! These bulbs use 90% less electricity, but are the same size (as well as the same base as the E12), and can fit into the same size lighting string socket as incandescents (note: this only applies to the retrofit bulbs being the same size and can fit into the incandescent socket, not single mold strings). The sockets on a C7 cord are slightly smaller than on a C9 cord. If you are looking for the brightest C7 and C9 bulbs, we recommend our new SMD bulbs which can provide 21st century technology with surface mounted LEDs. Both types of cords (socket wire C7 and C9) use a different base size of light bulb, and the C7 cord fits a candelabra base bulb (also known as an E12 base).

C7 strings and bulbs have a variety of applicable uses due to their smaller stature:

  • Edging gardens
  • Wrapping and hanging in trees
  • For parties
  • Strung along walkways on stakes or to highlight a path using stakes
  • Holiday displays

C9 LED Lights

C9 LED light bulbs will share the same energy efficient attributes as C7’s, but hold additional LEDs within their base. While both of these bulbs have the similar, “traditional” strawberry shape, you will notice that the C9 bulbs will be slightly larger and in some cases (if you are buying and hanging single mold light strings, rather than individual retrofit bulbs) they may produce less light. Unlike its counterpart, the C9 cords will fit an intermediate base bulb rather than a candelabra style (also known as an E17 base).

This larger size of bulb is more often used commercially, for larger scale decorations, and in malls and stores (or for those Christmas enthusiasts that go all out!). The C9 LED bulbs are often used on larger outdoor Christmas trees, and for outlining roofs and doors on commercial property. They are often chosen by churches to light their outdoor Nativity scenes, and by businesses to outline fences and other holiday displays.


Hopefully with this new knowledge on what exactly the differences are between these iconic LED lighting staples, your next lighting project will be stress and question free when it comes to choosing between C7 and C9 LED lights. For more information on bulb sizes, shapes, or uses please visit our LED Lighting Guide Blog for an answer to almost any lighting solution question you could have!

For more LED lighting tips, tricks, and knowledge, please visit our website to view our complete list of commercial LED products, as well as access to our incredibly knowledgeable and helpful staff who will help make your lighting dreams come true.

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