Electric Christmas lights began in the late 1800s and moved from candles and incandescent bulbs to LEDs, fiber optics, and addressable RGB systems. Today's options include incandescent, LED, fiber-optic, battery/solar, and programmable pixel strings. Common bulb sizes include C6, C7, C9, and globe sizes such as G30/G40. Look for safety listings and choose outdoor-rated, low-voltage, or LED options for efficiency and safety.

A short history of electric Christmas lights

Electric lights first appeared on Christmas trees in the late 19th century. In 1882 Edward Hibberd Johnson, an associate of Thomas Edison, displayed one of the earliest electrically illuminated Christmas trees. Through the early 20th century manufacturers and retailers helped move electric strings from specialty displays into homes. Companies such as those founded by Albert Sadacca and the later NOMA Electric Company played major roles in popularizing pre-wired colored light strings.

How the technology changed

Early displays used candles (a clear fire hazard) and then incandescent bulbs on wired strings. Incandescent strings remained common for decades because they were inexpensive and readily available.

From the 1990s onward, light-emitting diodes (LEDs) grew in availability and popularity. LEDs last longer, run cooler, and use far less electricity than incandescent bulbs. Fiber-optic trees and light sets also appeared, using a single light source to transmit color and pattern through fiber strands.

In the 2010s and 2020s addressable RGB LEDs and Wi-Fi/Bluetooth controllers added new capabilities: individually controllable pixels, color-changing effects, and smartphone control. Low-voltage and solar-powered outdoor options have also expanded the choices for safe, energy-efficient displays.

Types of Christmas lights today

  • Incandescent string lights: traditional warm glow, still sold but consume more power and run hot.
  • LED string lights: available in fixed-color and color-changing varieties; durable and energy-efficient.
  • Addressable RGB/Pixel lights: allow animations and per-bulb color control for custom effects.
  • Fiber-optic trees and strands: use optical fibers for soft, even color changes from a central light source.
  • Battery and solar lights: portable options for wreaths, garlands, and outdoor areas without easy outlets.
When shopping, look for markings from safety labs (UL, ETL, CSA) and labels indicating indoor or outdoor use.

Common bulb sizes and terms

Manufacturers use several standard shape/size codes. Approximate diameters below:

  • C6 (mini): about 3/4 inch (19 mm)
  • C7: about 7/8 inch (22 mm)
  • C9: about 1 1/8 inches (28-29 mm)
  • G30/G40 (globe): about 30 mm and 40 mm respectively
  • T (tubular) and LED "5 mm" types: small tubular or round LEDs often listed as T1-3/4 or 5 mm
These codes describe bulb shape and relative size; different manufacturers may use slightly different formats.

Practical notes

For outdoor use, choose sets rated for exterior environments and protect connections from water. For longer life and lower energy use, LED sets are generally preferable. Store light strings untangled in a dry place to reduce wire fatigue and bulb loss.

FAQs about Christmas Tree Lights

Are LED Christmas lights safer than incandescent?
LED lights run cooler and use less electricity than incandescent bulbs, reducing fire risk and energy use. Still follow product safety ratings and use outdoor-rated sets outside.
What does C6, C7, or C9 mean?
Those codes describe bulb shape and approximate size. C6 is a small "mini" (~3/4 inch), C7 is slightly larger (~7/8 inch), and C9 is larger (~1 1/8 inches). Exact dimensions can vary by maker.
Can I use indoor lights outdoors?
No. Indoor-rated lights lack weatherproofing. Use only sets labeled for outdoor use to avoid electrical or fire hazards.
What are addressable or pixel lights?
Addressable lights let you control individual bulbs (pixels) for animations and color effects, often via a controller or smartphone app.
How should I store strings of lights?
Wind them neatly on a spool or wrap them around a flat organizer, keep bulbs and wires dry, and store in a cool, dry place to prevent damage.

News about Christmas Tree Lights

Covent Garden Has Announced The Return Of Its Stunning Christmas Lights – There Are Less Than Three Weeks To Go Until They’re Switched On - Secret London [Visit Site | Read More]

The 2025 Rockefeller Center Christmas Tree: From East Greenbush to the Heart of New York City - Rockefeller Center [Visit Site | Read More]

Leicester Christmas lights switch-on to launch festive season - BBC [Visit Site | Read More]

Hitchin set to sparkle as Christmas Tree Lights Switch-On returns for 2025 - Hitchin Nub News [Visit Site | Read More]

A guide to London's Christmas lights - London Evening Standard [Visit Site | Read More]

Join us for the official Ipswich Christmas Lights switch-on - ipswich.gov.uk [Visit Site | Read More]

Christmas lights switch-on to mark start of festive season in Ipswich - Ipswich.co.uk [Visit Site | Read More]