Best Slime Activator

If you’ve ever searched for the best slime activator, you’ve probably seen a dozen different answers — borax, contact solution, laundry detergent, Magical Liquid, saline solution… it can get confusing fast.

We’ve tested the most popular slime activators side by side using the same glue and method to see which one actually works best. Below you’ll find our honest results, texture comparisons, troubleshooting tips, and a simple explanation of why slime activators work in the first place. Whether you’re making glossy slime, clear slime, or a basic stretchy batch with the kids, this guide will help you choose the right activator every time.

 

Best Slime Activator (Tested & Compared)

After testing contact solution (with baking soda), borax solution, and Elmer’s Magical Liquid, here’s what we found:

We find contact lens solution to be the most consistent activator for slime. It’s the easiest to control, and it gives slime a soft and stretchy texture. We especially love using it for clear glue slime.

Borax in water is a very strong activator, so you have to be careful when adding it. Borax is the best choice for thick, structured slimes like glossy slime or iceberg slime.

Elmer’s Magical Liquid works, but it gave us inconsistent results. It also requires a lot more product than what the bottle states.

Keep reading for more details about our tested slime activators, other slime activator options, and even some slime troubleshooting!

What is a slime activator?

A slime activator transforms runny glue into stretchy, squishy slime.

Most white glues and clear school glues contain PVA (polyvinyl acetate). Slime activators contain borate ingredients (such as sodium borate or boric acid). When the borate ingredients mix with PVA glue, they create tiny links between the glue molecules, creating slime!

Contact Solution + Baking Soda (Our Favourite Slime Activator)

Contact lens solution is one of the most popular slime activators. It’s our go-to in all of our slime recipes, and after testing it against other activators, we’ve confirmed that it’s our favourite.

It’s important to know that not all contact solutions will work. The ingredient list must contain boric acid or sodium borate. If it doesn’t list one of those, it won’t activate slime.

Contact lens solution must also be used with baking soda. Baking soda helps create the right chemical environment for the borate ingredients to work properly. Without baking soda, the slime often won’t form correctly.

How to use it:

• Add 1 teaspoon baking soda to 1/2 cup glue
• Add 2-1/4 teaspoons contact solution slowly
• Mix and knead thoroughly
• Add more solution gradually, if needed

Texture results:

• Clear glue slime: Soft, glossy, and very stretchy.
• White glue slime: Similar to the clear glue slime, but slightly thicker and fluffier. It’s soft and easy to handle.

Why we recommend contact solution for making slime:

• Easy for beginners to control
• Inexpensive
• Easy to find
• Consistent
• Gentle on hands

Borax Solution

Borax has been one of the most common slime activators for years. It’s also the strongest slime activator, because it offers a much higher concentration of pure sodium borate. That strength can be useful for specialty slimes, but it makes it tricky to work with, especially for beginners.

How to make borax solution:

• Add 1 teaspoon borax powder to 1 cup hot water
• Stir to dissolve
• Cool to room temperature before using

How to use it:

• Add about 3 teaspoons of borax solution to 1/2 cup glue
• Stir well
• Mix thoroughly with your hands
• Add more solution gradually, if needed

Best for:

• Glossy slime
• Iceberg slime
• Spider Web slime
• Other thick specialty textures

Conclusion:

We find borax works especially well when you’re aiming for a specific texture or adding more complicated ingredients (like instant snow).

For basic slime, borax is a lot less forgiving than contact solution. It’s:

• Easy to over-activate
• Chunky feeling when mixing
• Easy to make the texture too rubbery

Elmer’s Magical Liquid

Elmer’s Magical Liquid is a thick, clear pre-mixed activator designed to replace contact solution and baking soda.

The bottle recommends starting with 2 teaspoons per 4 ounce or 6 ounce bottle of glue. In our testing, we needed closer to 5 teaspoons before slime formed properly. At that point, it felt slightly overactivated (tough to stretch) and under activated (still sticky!) at the same time, which was weird…

Texture Results:

• White glue slime: We didn’t love the feel of it at first. But after sitting in an airtight container for a week it ended up feeling perfect. Almost fluffy and really nicely stretchy… but not worth waiting that long for.
• Clear glue slime: We didn’t have much luck with it. It wouldn’t form proper slime and after a week it had mostly melted back into sticky glue. Odd!

Conclusion:

Because of how much product is required, and the higher price compared to contact solution, we wouldn’t recommend it as the best value option. It also didn’t work very well for us, in general.

The label of the small bottle suggests it makes 8 slime recipes per bottle, but realistically, it feels like you may only get four or five batches.

Other Slime Activators

Amazon Basics Slime Activator:

This slime activator seems similar to Magical Liquid and a lot of other slime activators out there. It replaces contact solution and baking soda, but like other pre-mixed activators, it can be more expensive.

Liquid Starch:

Liquid laundry starch works to make slime, so long as it contains sodium borate. Purex Sta-Flo, a popular brand for years, has been discontinued, but brands like Linit laundry starch will work. It can be harder to find, though, and isn’t available for purchase in Canada.

Laundry Detergent (like Tide):

Slime made with laundry detergent is a popular gimmick, but it’s less consistent than the other options. As long as the detergent contains boric acid or sodium borate it will work with glue to create slime. However, detergent formulas change often and the ingredients are more hidden on packages nowadays. It’s also harsher on skin, so we don’t recommend it as a primary activator.

Saline Solution:

Saline wound solution by itself is only sterile salt water, so it won’t activate slime. You need to buy saline solution that contains boric acid or sodium borate. Always check the ingredient list.

Eye Drops:

Using eye drops for slime was a bit of a fad for a while, but we don’t recommend it. Some eye drops contain boric acid and may work, but they’re expensive and inconsistent. We don’t recommend it for regular slime making.

Slime Activator Troubleshooting

Why won’t my slime activate?

There are a few reasons that might explain why your slime isn’t activating:

1. Your contact solution doesn’t contain boric acid or sodium borate.
2. You forgot to add baking soda in with contact solution slime.
3. You’re not using PVA glue.
4. You haven’t added enough activator.
5. You need to knead the slime longer.

Why is my slime sticky?

Your slime may be sticky if there isn’t enough activator in it, or if it needs more kneading. Try kneading it first, and if that doesn’t work, add more activator a few drops at a time.

Why is my slime rubbery?

If your slime is rubbery it means that it’s over-activated — i.e. you added too much activator. You can fix this by adding a small amount of warm water, or adding in a bit more glue. Knead it in thoroughly and check the slime consistency.

What’s the strongest slime activator?

Borax solution is the strongest because it contains the highest concentration of sodium borate. This is why you have to be careful when working with it — just a little bit of added activator can turn your slime from sticky to overactivated.

Can I make slime without borax?

Technically, no. All standard slime requires borate ions to form — whether from borax powder, contact solution, liquid starch, or detergent. You can make a few different slime recipes without borax, but they’re not quite the same as traditional slime.

If you’d like to try making slimes with different textures, you can try any of our edible slime recipes or learn how to make slime without glue.

What glue works best for making slime?

Any PVA (polyvinyl acetate) glue will work. We prefer Elmer’s glue because it’s reliable, easy to find, and consistently gives us the best texture results.

Slime Safety

When used properly, slime is generally safe for supervised play. However:

• Do not ingest slime or activators.
• Wash hands before and after playing.
• Avoid use on broken skin.
• Discontinue use if irritation occurs.
• Always supervise young children.

Borax products, especially pure Borax powder, should be handled responsibly, as you would any household cleaning product.

Here’s some of our favourite slime recipes:

Crunchy Slime

Jelly Cube Slime

Putty Slime

Where to buy:

You can purchase Low-Mess Crafts for Kids from Amazon, or wherever books are sold:

Amazon | Barnes and Noble | Books-A-Million | Indiebound | Amazon Canada