The best C6 Christmas lights, and how they differ from C7 and C9

How we ranked these

Published count and published length first, because together they give the spacing and spacing is the reason anyone buys C6 instead of C9. Then construction: whether the bulb screws into a socket or is sealed to the wire. Then wire color and bulb color, which are the decisions you cannot change later. Then whatever the listing says about joining strings end to end.

We do not rank on brightness. No C6 listing in this field publishes a lumen figure per bulb, and one C6 bulb is not a product anybody buys on its own; the string is the unit, and the string is what these figures describe.

What a C6 bulb is, and what no listing will tell you

C6, C7 and C9 are bulb-base and bulb-shape designations, and the numbers run in the direction you would expect: C6 is the smallest of the three, C9 the largest. That is as far as the listings go. Not one C6 string in this field publishes a bulb diameter or a bulb height, and neither do the C7 and C9 strings we rank on their own pages. If you want the physical size of the bulb, you are measuring one in your hand or you are trusting a photograph.

What the listings do publish is the count and the length, and that turns out to be the more useful pair anyway. Bulb size decides how a single bulb looks close up. Spacing decides how the run looks from the sidewalk, which is where every decoration is actually judged.

C6 against C7 and C9, on the figures that exist

This is the comparison people search for, and it is answerable in one line of arithmetic. The C7 and C9 commercial strings we rank on the C7 page and the C9 page publish 25 bulbs over 25 ft, which is a socket every 12 inches. The C6 strings here publish about four inches.

Two practical consequences fall out of that ratio. First, C6 needs more strings to cover the same distance, so the cost per foot is usually higher than it looks per string. Second, C9 reads from much further away: a big bulb every foot is legible from across a street in a way that three small bulbs per foot is not. If the display is meant to be seen from a passing car, that is the argument for going bigger, and it is worked through on choosing the bulb format first.

The third consequence is electrical, and it runs the other way. Three times the bulbs is not three times the load, because an LED C6 draws a fraction of a watt; but it is still more bulbs on the circuit, and none of these C6 listings publishes a wattage. The C7 OptiCore string on our C7 page publishes 0.8 W per bulb and a 480 W end-to-end limit, which is exactly the kind of figure that lets you plan a run. Work your own total through how many amps a display draws before you add a fourth string to a circuit.

How many strings a tree or a run takes

C6 is bought by the count far more often than by the foot, because most of it goes on trees and bushes rather than along a straight gutter. The site convention for a fully lit tree is 100 lights per vertical foot, and at that density C6 strings add up quickly.

For the tree arithmetic in full, including density by tree height rather than by string, see how many Christmas lights do I need and the lights calculator.

One piece or a socket

The single construction difference worth understanding in C6 is whether the bulb sits in a socket or is sealed to the wire. The YULETIME string publishes one-piece construction, which means the LED is molded into the lens and the lens into the wire. There is no socket, and a socket is where water collects and where corrosion starts on an outdoor run.

The trade is repairability. A socketed string lets you swap one dead bulb; a one-piece string does not, and when a section goes the string is replaced. On modern LED sets that matters less than it used to, because the common failure is a wire or a rectifier rather than a single diode, but it is the honest cost of the sealed design. Our troubleshooting guide covers which failures are worth chasing.

Joining strings, and the limit nobody publishes

One C6 string rarely finishes a job. Joining them is normal and safe within a published limit — and a published limit is exactly what this category does not have. The FGDECORJOIE string is the only one here that says it is connectable at all, and even it gives no maximum. That is a meaningful gap against the commercial C7 and C9 strings, which publish both a wattage per bulb and an end-to-end figure.

In the absence of a published limit, the safe practice is the conservative one: keep joined runs short, use the manufacturer’s own fused plug rather than an adapter, and count the total load yourself. The mechanics of joining, and what the fuse in the plug is actually protecting, are on connecting light strings.

Why the spool set is the skip

The 150-bulb spool publishes a count and nothing else. On a 150-bulb string the spacing could be three inches or eight, and those two strings look nothing alike and cover wildly different distances — somewhere between 37 ft and 100 ft on the same published count. A spool is a bulk format, and bulk is where the length matters most, because you are buying it to run somewhere specific.

The Wintergreen multicolor string has the same missing figure and keeps its place only because it is the one multicolor option here and because the brand publishes far more on its larger bulbs. If you want multicolor C6, it is the one to buy; just measure it when it arrives.

Where C6 fits in the rest of the display

C6 is the close-range format: trees, bushes, railings, doorways, wreaths. The roofline is usually C7 or C9 for the reach, the eaves are usually icicle lights, and the path is its own job on Christmas pathway lights. Before you buy anything, the LED-against-incandescent decision sets the running cost and the number of strings per circuit: LED vs incandescent has that arithmetic in full, and Christmas tree lights covers what goes on the tree itself.