4th September 2025
What Is the Best Activator to Make Slime? (A Complete Guide)
If you've ever tried to make slime you've likely asked: What's the best slime activator? It's easy to get overwhelmed by options like borax, contact lens solution, and baking soda. In this guide, we'll break down the most effective slime activators.
DIY Team
What Is the Best Activator to Make Slime? (A Complete Guide)
If you've ever tried to make slime at home or in the classroom, you've likely asked: What's the best slime activator? With so many DIY recipes floating around, it's easy to get overwhelmed by options like borax, contact lens solution, and baking soda. In this guide, we'll break down the most effective slime activators, how they work, and which one is best for different types of slime.
What Is a Slime Activator?
A slime activator is the ingredient that turns your slime mixture from a sticky glue mess into that stretchy, gooey texture we all love. It usually reacts with polyvinyl acetate (PVA) — found in white school glue — to create cross-links that transform the glue into slime.
Top 5 Best Slime Activators (Ranked)
Here are the most popular and effective slime activators you can use:
1. Borax Powder (Sodium Tetraborate)
How it works: Dissolved in water, borax creates a solution that cross-links with glue.
Best for: Classic slime textures, strong stretch and bounce.
Pros: Reliable, widely used in slime recipes.
Cons: Can irritate skin; not ideal for younger kids.
2. Contact Lens Solution + Baking Soda
How it works: The baking soda helps thicken the glue, and the boric acid in the contact lens solution acts as the activator.
Best for: Fluffy slime, glitter slime.
Pros: Safer alternative to borax; available in most households.
Cons: Some brands work better than others; requires trial and error.
3. Liquid Starch (e.g., Sta-Flo)
How it works: The starch contains sodium borate, which acts as a binder.
Best for: Glossy, smooth slime.
Pros: Easy to use, pre-mixed.
Cons: Not as stretchy; can dry out quickly.
4. Saline Solution
How it works: Similar to contact solution, it contains boric acid and sodium borate.
Best for: Soft, smooth slimes.
Pros: Gentle on hands, good for beginners.
Cons: Not as thickening without baking soda.
5. Laundry Detergent
How it works: Contains borates or similar chemicals that bond with glue.
Best for: Quick and easy slime.
Pros: No extra ingredients needed.
Cons: Some detergents don’t work; fragrance may cause irritation.
Expert Tip: Our Favorite Combo
From our experience, contact lens solution + baking soda strikes the best balance between safety, accessibility, and performance. It’s especially ideal for kids and schools.
FAQs
What is the safest slime activator for kids?
Contact lens solution with baking soda is widely considered one of the safest options. Always check for boric acid in the ingredients.
Can I make slime without an activator?
Technically no. You need an ingredient that reacts with the glue (even natural alternatives like psyllium husk or cornstarch act as mild activators).
Why is my slime too sticky?
You likely didn't use enough activator. Add a small amount at a time and knead well.
What brands of contact lens solution work best for slime?
Popular slime-friendly brands include Renu, Equate, and Opti-Free — just ensure they contain boric acid.
Is borax banned in slime making?
No, but some countries restrict it due to potential skin irritation. It's safe with adult supervision.
Conclusion
The best slime activator depends on your needs: Borax for classic slime, contact solution for safety, and liquid starch for ease. Understanding how each option works helps you create the perfect slime every time. Try a few and see which texture you love most!
