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C7 vs C9 Christmas Lights: What Should You Use?

C7 and C9 are a few of the Christmas lighting options available.

Both C7 and C9 are versatile multi-use decoration lights. They make excellent interior and exterior Christmas decor lights. C9 is intensely bright, making it the best outdoor Christmas light. C7 lights are small, making them ideal for indoor decoration and small spaces.

They come as transparent or opaque lights. The transparent options come wrapped in a coating that allows you to see the bulb.

The opaque version, on the other hand, gives a colored glow. They both have a sparkling glow, making them favorite festive lights.

What are C7 Lights?

C7 vs C9 Christmas Lights: What Should You Use? 1
C7 Green LED Christmas Light Bulbs

These are small base lights used during the Christmas decoration season. They work best for small-sized indoor and outdoor Christmas trees. C7s are also perfect for outlining the edges and roofs of smaller houses.

What are C9 Christmas Lights?

C7 vs C9 Christmas Lights: What Should You Use? 2
C9 LED Christmas Lights

These are lights that use the C9 bulb in their construction. They often work best in commercial buildings as roof outlines for larger buildings. You will likely see these lights at restaurants and government buildings.

Quick Comparison of C7 and C9 Christmas Lights

  • C7 lights are excellent for retro-style decoration, while C9 lights are not.
  • C7 lights are 2 inches long, while C9 ranges from 2 and ¾ inches to 3 inches.
  • C7 lights base is E-12 candelabra, while C9’s base is E-17 intermediate.
  • C7 lights have 5 or 7 watts, whereas C9’s incandescent bulbs are either 7 or 9 watts.
  • C7 lighting isn’t great for outdoor tree decoration, while C9 is.

C7 vs C9 Christmas Lights – The difference that Matters

What you choose depends on the style you go for. For example, retro looks need C7 lights. Consider using LED lights to save more energy with this style.

Besides that, LEDs are brighter in appearance. They are also cool to touch; hence no accidents will occur.

C7 lights also use smaller bulbs. You will thus need more lights to decorate a larger space. So choose to use C9 lights instead for larger areas.

Generally, C7 lights are useful for decorating items within a viewer’s eyesight. But, C9 Christmas lights work best when decorating items seen from a distance. So, go for C9 lights if your decorated pieces are far away.

Consider the bases of the two lights when buying, as this affects their sizes. For example, the C7 Christmas light bulb base is an E-12 candelabra. The C9 Christmas light bulbs have a bigger, E-17 intermediate-size base.

The Size Difference and Light Application

C7 bulbs are smaller compared to C9s. They are about 1 1/2 inches long and come in 5 watts for incandescent bulbs. The C7s have an E12 candelabra base, like an ordinary night light bulb.

Most clients choose 4-watt C7 bulbs. But, this wattage may vary. If you want a brighter option, then the 7-watt incandescent bulbs work. Use brighter options on the roof linings/ driveway outlines/ string them on pergolas.

C9 bulbs are more than 2 inches long, which makes them more prominent. They fit on an E17 base and are often available in 7 or 10 watts for incandescent bulbs. You can use them as the C7 lights but in larger spaces.

Note that C7s or C9s incandescent bulbs get hot over time when used. Thus, keep them off from flammable dec pieces. Avoid using them on flammable trees too.

Many C7 & C9 light applications need connections to a power source. They come with a socket attached to one stringer line with many sockets.

Stringers also have a fuse in their male plug end of the line. These fuses only allow less than 700 watts per connected line.

Of course, you can permanently remove the socket to get more lights per strand. Be cautious since this is dangerous unless you know the copper line’s actual power capacity.

Using LED Lights

Using C7 LED light bulbs is a better alternative. You’ll use 90% less electricity with your Christmas light or without changing the size. They also fit into similar size bases as the previous incandescent lights.

C9 LEDs also have similar essential attributes. The only difference is that they have 5 LEDs on their base. They come with 3 LEDs for each base and are available in faceted, smooth, or dimmable finishes.

Dimmable bulbs are the best for both LED lighting options. Play around with the finishes or effects as you would with the incandescents.

LEDs of both the C7 & C9 strings use about a tenth of incandescent power wattage. Compared to incandescent options, using ten times more bulbs on one run of LEDs is possible.

While these bulbs never get hot, it is better to take caution and avoid using them on trees. Only do this if the bulbs have a fused socket that is removable.

Most users hang such lights on pine/evergreen trees. You must be careful when using non-fused light string. One pine needle can cause a fire when it gets into the socket.

Using C7 Bulbs to Decorate

With LED bulb varieties, it is possible to work out any style. For example, go for Incandescent-vintage-like LED bulbs when decorating high-end residential spaces.

These are great for roof outlines and gazebos. They are also timeless regardless of the season. Use them for edging gardens and wrapping and hanging on trees. They make fantastic garlands and wreaths too.

These lights create a festive retro perfect for parties and strung along walkways. You can also hang them on trees to form a canopy.

The vintage look they create works for holiday displays. Note that the opaque bulbs are pleasant even when unlit. Moreso in historic buildings.

Decorating with LED C9 Bulbs

These are larger bulbs. They are great for commercial establishments. C9 work best for larger-scale decorations in malls and larger stores. 


Is C7 or C9 lights better?

Yes. C7 LED bulbs use less electricity (90%) than incandescent lights. But you can fix them in the same base as incandescent light because of their similar sizes. Overall, these lights have 3 LEDs in each base. They also come in faceted, dimmable, and smooth finishes. C9, on the other hand, has 5 LEDs at its base and similar essential traits to the C7s.

Can you use C9 lights on a Christmas tree?

C9 lights are standard outdoor Christmas lights. They are often hung on trees outside the house because of their bright light. This bright light might be intense when used indoors or in small spaces. You can buy the c9 light strings in sets or individually. It also has a wide range of customization options.

Final Thoughts

C7 vs C9 are great Christmas lights. It is best to consider their use before buying either. Settle for the lights that are likely to serve you best.

This video explains the difference between c7 and c9 Christmas lights.