How To Make a String Duper Minecraft

Introduction.

If you’re like me, you’ve probably run into this problem: you need a ton of string in Minecraft, but killing spiders or looting desert temples just isn’t cutting it.

Whether you’re making wool, fishing rods, bows, or even tripwire hooks, string is one of those items you always seem to run out of when you need it most.

That’s where a string duper comes in.

Now, before anyone starts raising eyebrows—yes, duplicating items might sound a little shady at first. But here’s the deal: Minecraft is a sandbox game. It’s all about creativity, experimentation, and finding cool ways to solve problems.

Duping string isn’t cheating unless you’re doing it in a competitive or shared server without permission.

If you’re in your own survival or creative world and just want to speed things up a bit, this method is totally fair game.

So, let’s talk about how to actually make a string duper, why it works, and how to use it efficiently without breaking your world.

What Is a String Duper in Minecraft?

A string duper is a redstone-powered contraption that takes advantage of how Minecraft handles game mechanics—particularly minecart physics and block updates—to duplicate string using tripwire blocks.

It’s a type of block update dupe, and it’s often used by experienced players in survival worlds who need bulk resources without grinding forever.

Just to be clear: this method doesn’t involve any external tools or mods. It’s done using vanilla Minecraft mechanics that exist in the game itself. That said, Mojang tends to patch dupes in updates, so make sure you’re on the right version.

What Version Does It Work On?

This method works best in Minecraft Java Edition—specifically around version 1.16.5 to 1.20.1. Newer versions like 1.20.2 and beyond may have fixed or altered these mechanics, so if you’re not seeing results, try using an earlier version.

✅Tip: Always back up your world before trying any kind of dupe glitch. Just in case.

Why Duplicate String?

Here’s why I use a string duper:

• Wool farms – Need string to convert into wool with looms or for trading with villagers.

• Trading with fletchers – They love string and give emeralds.

• Scaffolding – Super useful, but requires string and bamboo.

• Fishing gear – Making a bunch of enchanted fishing rods.

• Tripwire traps – Lots of tripwire = more creative trap builds.

Honestly, it just saves a bunch of time and makes everything smoother when you’re building or automating your world.

Materials You’ll Need

Let’s keep it simple. Here’s what you need to build a basic string duper:

• 2 Pistons

• 1 Redstone Block

• 2 Slime Blocks

• 2 Observers

• 2 Tripwire Hooks

• 1 Piece of String

• 1 Sticky Piston

• Building Blocks (like stone or dirt)

• Optional: Lever or Button to trigger the dupe

This setup is pretty small, and you won’t need any rare items—just a bit of redstone knowledge and a few minutes.

How do I Make a String Duper?

Let’s get right into it.

Step 1: Place Your Foundation

Lay down a few blocks to act as your base. You’ll build the mechanism on top of this.

Step 2: Set Up the Tripwire

Place two blocks three spaces apart, facing each other. Add a tripwire hook on each one and connect them with 1 piece of string. That’s your trigger.

Step 3: Add Pistons and Observers

On one side of the tripwire, place a piston facing toward the hook. Behind that, place an observer so that it detects when the string gets triggered.

Repeat on the other side, mirroring the setup. When powered, the pistons will extend and retract quickly due to the observer clock.

Step 4: Add Slime Blocks and Redstone

Attach slime blocks to the pistons, and place a redstone block so that when the slime block moves, it powers the system again. This causes a rapid chain of updates.

Step 5: Add Sticky Piston (Optional Reset)

If you want to make your duper toggleable, add a sticky piston to push the redstone block in and out of place using a lever or button.

Step 6: Activate It

Trigger the duper by updating the system (e.g., placing or removing a block near the observer). The game gets confused by the update chain and duplicates the string from the tripwire.

Boom—extra string appears.

Does It Work in Multiplayer?

Technically, yes—but be careful. Most multiplayer servers (especially those running Spigot or Paper) patch these kinds of glitches.

You could get banned or flagged for exploiting if you use this on someone else’s server. So always check with the server rules first.

Is Duping Safe?

It’s pretty safe if you don’t overdo it. Massive redstone contraptions can cause lag, especially if the duper runs in an infinite loop. I recommend using it in short bursts and shutting it off when you’re done.

If you’re worried about breaking your world, test it in a creative copy first. Just to be sure.

Minecraft Community Thoughts

Duping is always a hot topic in the Minecraft community. Some players love the challenge of gathering everything by hand, while others are totally fine using dupers to speed things up—especially in long-term survival worlds.

A good place to explore community builds is the r/technicalminecraft subreddit.

There are tons of designs, videos, and posts from experienced players sharing their favorite dupers and farms.

FAQs

Can I get banned for using a string duper?

Only on public or multiplayer servers with rules against it. In single-player, it’s your world—do what you want.

Is this allowed in Minecraft Bedrock Edition?

Most dupers don’t work in Bedrock because of differences in how the game handles redstone and block updates. You’ll likely need a separate method or use add-ons.

Does Mojang plan to remove this?

Duplication glitches usually get patched over time. If it’s a mechanic you depend on, stick to older versions or keep backups.

What’s the best way to use all that string?

Trade with fletchers, craft scaffolding, make bows, fishing rods, tripwire traps, or use it in redstone builds. It’s surprisingly useful.

Alternatives to Duping

If you’re not comfortable duping, you can still build:

• Spider XP farms – Use a dungeon spawner to farm spiders and collect their drops.

• Cave spider farms – More efficient, but trickier to set up.

• Bartering with piglins – They sometimes drop string too.

• Trading with villagers – String for emeralds (or vice versa, depending on the trade).

These methods take more time, but they’re fully legit.

Final Thoughts

So yeah, making a string duper isn’t hard—and it can really save you time when you’re knee-deep in survival projects. Just remember: use it responsibly, back up your worlds, and don’t go wild with redstone clocks unless you want a laggy world.

If Mojang ever patches it, you’ve got backups and alternatives to fall back on.

Have you tried building a string duper before, or do you prefer playing without duplication tricks?