Is a Basking Light the Same as a UVB Light?

When raising reptiles or amphibians, you want to make sure they have everything they need to lead happy, healthy lives in your terrarium. But sometimes, understanding the ins and outs of proper terrarium lighting can be a little confusing. Your pets need UVB light, and they need to bask under warm rays. But is basking light the same as UVB light? No! Keep reading to learn the differences.


Why Your Reptiles Need UVB Light

UVB light isn't just a luxury for your reptile pets — it's a necessity. That's why ultraviolet lightbulbs for terrariums typically provide both UVA and UVB light. Reptiles can see UVA, which helps regulate their day and night activities, breeding, endocrine systems, and overall mood.

They can't see UVB, but it's still equally important to their health. UVB exposure helps synthesize vitamin D3, which lets them maintain optimal calcium levels. Without it, they might develop fatal nutritional diseases. Having ample vitamin D3 also supports their immune system and basic functions like cell division.

In the wild, reptiles and amphibians get their UVB exposure from the sun. In your terrarium, you need to mimic sunlight with UVB bulbs. Why? Natural sunlight gets filtered through windows and glass, which scatters and blocks some much-needed UVB rays.

Tip: Check out the Zilla Habitat Guide to help determine your pet's specific UVB needs.)

Are Basking & UVB Bulbs the Same?

Since reptiles in the wild get UVB exposure when they bask in the sunlight, you may naturally assume that basking bulbs are the same as UVB bulbs. But typically, this isn't the case.

It can get a little confusing, but it boils down to this:

  • Most basking bulbs are incandescent or halogen bulbs that emit heat and some light visible to humans and reptiles but not any form of UV light (including UVB or UVA light).
  • Most fluorescent terrarium bulbs provide needed UVB (and UVA) but do not provide enough heat for basking.
  • There are only a few exceptions. Mercury vapor bulbs and metal halide UVB lamps can emit both basking heat and UVB, but some produce heat or UVB that's too intense, making them unsafe for your reptile buddy. (There are Mercury vapor bulbs designed specifically for reptiles and have safe levels of heat and UV.) So do your research before purchasing these.

Most terrariums typically use a combination of fluorescent bulbs that provide UVB (and UVA) light, along with basking bulbs for heat.

For example, Zilla has a series of incandescent bulbs used for basking but don't emit any form of UVB (or UVA) light. These include the Zilla Day White Light bulbs, which are great for daytime basking, and the Zilla Night Red bulbs for nocturnal heat. Zilla also has basking heat projectors that provide 24/7 heat without visible light, UVB or otherwise.

If you use any of those items, you also want to get the Zilla Tropical or Desert fluorescent bulbs, which don't provide basking heat but do provide the UVB (and UVA) light your pet needs.


If you're not sure how to put all these bulbs together in your terrarium, you can find fixtures that help. The Zilla Heat & UVB Basking Fixture accommodates both a fluorescent coil bulb and a mini halogen bulb, helping you meet both UVB and basking needs.

In short: the only way to know for sure if the basking bulb you're considering also emits UVB is to read the label. Most of the time, you'll need both a fluorescent UVB bulb and a basking bulb.

You Need a UV Detector to Know When It's Time to Change Your UVB Bulbs

Once you've set up the UVB bulbs in your terrarium, your job isn't over. You need to track when it's time to change them. And it's not as easy as just checking to see if the bulb is still shining. UVB bulbs will continue to shine long after they no longer emit the UVB your pet needs.  So, you need help knowing when to replace the bulbs.

The Zilla Rapid Sense Decor provides a UV detector that tells you when to change the bulb. The detector is located beneath the feeding cup for large sizes and beneath the decor itself for medium sizes. Just hold it under your UVB light for about 30 seconds, and it will change color to let you know if it's time to change the bulb. The decor comes in two designs: Poplar Log and Crocodile Skull. Both provide space for basking and hiding, ensuring your scaly buddy enjoys using them too.

Rapid Sense Guide

When setting up lighting and heating for your reptile pets, you want to do your research. In most cases, you need both UVA and UVB bulbs and basking lamps to meet your tiny dragon's habitat needs. Adding a UV detector to the mix helps ensure their lighting remains at optimal levels.