How to Shorten Outdoor LED String Lights?

Outdoor LED string lights provide a beautiful way to decorate gardens, patios, gazebos and other exterior spaces. Their connected string design allows shaping lighting to any area. However, sometimes the strands come in lengths too long for the intended space. Rather than coiling up excess lighting, the ideal solution is shortening the strand to the perfect custom size. With the right techniques, you can tailor outdoor LED string lights to fit your space perfectly.

This comprehensive guide covers planning shortened lengths, tools to use, safe cutting methods, reconnecting circuits, weatherproofing, troubleshooting issues, and specialized shortening considerations for Christmas lights versus year-round outdoor string lights. With the skills to properly modify string light length, you can adorn any outdoor spot with gorgeous, energy efficient LEDs.

Overview of Shortening LED String Lights

Shortening outdoor LED string lighting offers many benefits:

  • Custom fit strands to any unique outdoor space
  • Eliminates coiling or hiding excess strand length
  • Optimizes light placement and minimizes gaps
  • Creates cleaner setup without loose wiring
  • Prevents hazards from extra cabling
  • Improves power efficiency by removing unneeded LEDs
  • Less material waste and expense than buying new
  • Allows matching exact required lighting lengths

With proper shortening techniques, you can modify strands for picture perfect placement.

Should You Shorten Outdoor LED String Lights?

Ask yourself these questions when deciding whether to shorten LED strands:

  • Is the existing length way too long for the space?
  • Will shortening allow better light positioning?
  • Do you want to permanently mount the lights rather than temporary?
  • Are you comfortable working with electrical wiring?
  • Is the strand new enough to justify modification vs replacement?

If the excess cabling will create issues with placement and setup, taking the effort to shorten to an optimal length is likely worthwhile.

Tools and Materials Needed

You’ll need the following tools and accessories:

  • String light strand you want to shorten
  • Wire cutters with sharp flush snips
  • Wire strippers
  • Soldering iron and solder
  • Heat gun
  • Heat shrink tubing assortment
  • Electrical or masking tape
  • Wire nuts, crimp connectors or wago connectors
  • ZIP ties and mounting clips
  • Isopropyl alcohol and rags

Having the right supplies makes string light shortening much easier.

How Much to Shorten the Strand Length

If attempting to cover a specific area, first measure the space needing lights:

  • Use a tape measure to determine exact start/end points and total distance.
  • For wrapping applications like trees, measure around the full circumference.
  • Convert measurement to feet if the strand length is listed in feet.
  • Subtract about 1 foot from total to allow connecting slack.
  • Check that shortened length will still meet minimum string requirements.

Knowing the exact length needed for your space makes calculations simpler.

Where to Cut LED String Lights

  • Examine wiring carefully to locate cut points. Cut only at designated locations.
  • Copper pads – Some strings have exposed copper pads between LED lamps. Cut here.
  • Wiring joints – Kind of string lights have plastic molded junctions. Cut wires entering and exiting joint.
  • Mid-wire – If no plastic joint, cut into the insulation, being careful not to damage inner wires.
  • Never cut directly through LED lamps or drivers.

Cutting improperly can make reconnecting circuits very difficult or risk permanent damage.

How to Safely Cut Into LED String Light Wiring

Follow these safe steps when cutting into strings:

  1. Confirm power to lights is disconnected before cutting!
  2. Use wire cutters to carefully snip into the flexible outer plastic insulation. This allows accessing the internal wires safely.
  3. Peel back the cut insulation, being careful not to nick the inner wires. Copper strands should be visible.
  4. Avoid cutting wires deep enough to sever them completely. Keep intact for now.
  5. Make a small pilot cut first, then cut deeper in stages check for internal damage.

Making incremental cuts prevents accidentally cutting through and damaging delicate inner conductors. Go slow!

Technique for Shortening Plug-in LED Strings

Plug-in LED string lights typically have polarized plug connections. Modify them like this:

  1. Examine the prongs on the plug end and note which is wider. This is neutral.
  2. Trace the wires back from the wider neutral plug prong. Mark to identify.
  3. Near your cut point, cut into the plastic to access the inner marked neutral wire first. Avoid cutting it yet.
  4. Cut insulation from the opposite live power wire. Leave intact for now.
  5. Make pilot cuts in both wires then cut all the way through for removal.

Keeping polarity straight avoids issues powering up shortened stands.

Shortening Low Voltage LED Strings

For 12V or 24V low voltage strands:

  • Identify positive and negative wires using polarity markings printed on the cable.
  • Use an appropriate low voltage DC power adapter for the cut length to supply power.
  • Carefully match positive to positive and negative to negative when reconnecting wires.
  • Use joining methods like soldering, crimp connectors or wago connectors for reliable connections.

Mismatched polarity can prevent low voltage LEDs from lighting. Verify it is correct.

Reconnecting Cut LED String Light Wires

Here are options for rejoining cut wires:

  • Soldering – Provides strongest reconnect if properly done. Use non-acid flux core solder.
  • Wire nuts – Twisting wires together securely inside a wire nut creates a decent connection.
  • Crimp connectors – Uses metal teeth inside a sleeve to grip stripped wires when compressed. Requires special crimping tool.
  • Wago connectors – Easy push-in connectors that clamp down firmly on inserted wires. Great for solid core wire.
  • Twist on wire connectors – Available in different sizes to handle multiple wire gauges. No tools needed.

The optimal reconnection method depends on wire gauge, insulation, construction and your skill level.

Restoring Broken Circuits in LED Strings

If a cut severs the conducting circuit traces:

  • Examine closely to identify positive and negative circuit paths.
  • Solder thin jumper wires across the gap to bridge broken circuit connections.
  • Insulate exposed wires with heat shrink tubing to prevent dangerous shorts.

Carefully follow circuits and only reconnect matching poles using jumper wires to restore severed paths.

Weatherproofing Joints and Connections

Outdoor conditions require weatherproofing all connections:

  • Apply adhesive lined heat shrink generously over all spliced wire joints.
  • Heat to fully seal both waterproof adhesive and protective tubing.
  • Consider using UV resistant heat shrink when sunlight exposure is high.
  • Coat connections in flexible silicone sealant for added protection.
  • Encase wires in flexible silicone filled wire nuts for both securing and sealing.

Any points of connection must be resealed for permanent waterproof and corrosion protection.

Testing and Troubleshooting Shortened Strings

Before final mounting:

  • Inspect all connections closely under magnification to check tightness. Redo any concerning joints.
  • Examine string thoroughly checking for any lost continuity or dark spots indicating cut circuits.
  • Verify even bulb spacing down line with no gaps from severed circuits.
  • Power up shortened strand and confirm even illumination across all bulbs.
  • Mount a few feet and test again for at least 10 minutes before fully securing all lights.

Thoroughly checking your work helps identify any issues to correct before hanging all lights.

Hanging and Securing Shortened Strands

Outdoor LED strings should be hung securely:

  • Attach lights using insulated hooks, mounting clips or zip ties spaced at proper intervals.
  • Provide a little slack between attachment points to allow shifting from wind or temperature changes.
  • In damp locations, use zip ties or waterproof silicone filled hooks to resist corrosion.
  • Check that wiring is not pinched at any point by clips causing dangerous shorts or damage.

Properly anchoring strands prevents unsafe sagging over time while allowing flexibility of movement on the strand.

Special Considerations for Christmas Lights

Shortening classic Christmas style LED strings requires extra care:

  • Carefully note socket cap colors indicating polarity – typically green is negative and red is positive.
  • Christmas lights connect multiple bulbs in series. Cutting the wrong bulb will open the circuit. Trace wires fully if issues.
  • Bulb spacing may shift down the line after shortening. Compensate when attaching light sockets.
  • With older stands using screw-in bulbs, seal bulb bases with silicone once inserted to prevent moisture issues.

Incorrect cuts that disrupt the delicate series circuits quickly lead to darkened sections down the line. Be cautious!


Shortening too lengthy outdoor LED string lights allows perfect placement and eliminates messy coiled extra cable. With the right tools and some electrical know-how, you can customize strands by carefully cutting to length and reconnecting circuits. Just be sure to follow polarity markings, properly join wires, seal connections thoroughly, and inspect closely before mounting shortened strands. The result is LED lighting tailored exactly to your outdoor space. Take the time to properly measure and modify string lights and enjoy a clean, professional lighting installation.

FAQs About Shortening LED String Lights

Q: Is it safe to shorten LED string lights while powered on?

A: Absolutely not! Always modify lights only after disconnecting all power to avoid electrical shock risks.

Q: Can I lengthen rather than shorten LED strings?

A: It is possible by splicing in additional string sections, but runs may eventually become dimmer as voltage drops over distance.

Q: Can I cut waterproof outdoor LED strands?

A: Yes, you just need to properly reseal any opened connections thoroughly for permanent water protection after shortening.

Q: Will shortening LED strings affect the lifetime?

A: No, as long as cuts are done safely and strands reconnected properly, the remaining LED lamp lifetime will be unchanged.

Q: Is it worthwhile to modify older incandescent strings to LED?

A: Usually not worth the effort. Newer LED replacement strands are inexpensive and will be engineered to perform better.

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