Can A Smartphone Be Used As A Thermal Camera?

If you've ever called an HVAC specialist to inspect your home before, then you've probably noticed them often holding a camera-like device showing various shades of reds and blues. That's a thermal camera in action, and it's used for detecting thermal energy, a.k.a. heat, produced by both living things and objects. This helps them find the exact spots where you might be experiencing heat loss issues.

But there's more to thermal cameras than just checking for home energy problems. They can come in handy for a host of other tasks too. For instance, thermal cameras can capture wildlife at night, which can make for an entertaining activity when out camping. Some also use them to detect pests in the attic, diagnose car problems, and troubleshoot electrical and electronic systems.

While they're certainly multipurpose, thermal cameras can be quite pricey, usually costing at least $1,000 for the high-end models. They're also bulky to carry around. This poses the question: can you use your smartphone as a thermal camera instead? After all, it already comes with a built-in camera, it's more portable, and it's capable of different basic and advanced tasks.

Well, the answer to that is yes and no.

Browsing through the Play Store or App Store, you'll come across a bunch of free thermal camera apps that generate images similar to those taken by dedicated thermal cameras. These supposedly work out of the box with no setup. Just install them on your phone, launch the app, and voilà — you can start scanning the room for thermal anomalies.

Although the app's output does look like a real thermal camera view to the untrained eye, they're actually simulations only. The apps just apply filters over the video or photo to create the thermal effect. That said, they aren't accurate or reliable, so they're practically useless if you need to inspect your home for water leaks or your circuit breaker for electrical troubles.

If a thermal camera app does claim to provide "real results," don't fall for it. Thermal imagers work because they have a special hardware, the infrared detector, which helps the camera see heat emissions in the area. Mainstream smartphones, while loaded with various phone sensors, don't normally have an infrared detector built in. This means they can't capture what real thermal imagers do, regardless of what app is installed.

It's important to note though that not all thermal camera apps are fake. There are some legitimate ones out there, but they aren't standalone. They need to be paired with external hardware. Otherwise, you can't use them at all.

Although mainstream phones like iPhone, Google Pixel, and Samsung don't come equipped with a built-in thermal sensor, you can actually find some that do. For instance, there's the CAT S60, dubbed as the first-ever thermal imaging smartphone. It was developed by heavy equipment manufacturer Caterpillar for rugged settings and featured a FLIR thermal camera. Other thermal camera smartphones on the market include the Ulefone and Blackview devices, most of which also have a FLIR camera, and the AGM phones that integrate its own thermal technology.

For most of these smartphones, you can find an accompanying thermal app already pre-installed on the device. Use this to take a picture, record a video or time-lapse, and adjust the thermal camera settings. On top of thermal scanning, these devices work like any other regular smartphone. They usually run Android OS and let you watch YouTube videos, make calls, and browse the web.

The thing about most of these thermal phones, though, is that they're ruggedized for the outdoors or professionals at worksites. That said, expect them to be heavier. While the Pixel 9 Pro XL weighs only 7.8 oz, the AGM G2 Pro is almost double at 14.3 oz and the smaller Ulefone Armor Mini 20T Pro is at 10.6 oz. Some users have noticed a lack of regular software updates on these kinds of phones, so if you're big on having the latest and freshest features and are concerned about long-term compatibility, they might not be the device for you.

What if you don't want to buy an entirely new phone just to get your hands on thermal technology? In that case, what you're looking for is a mobile-compatible thermal imaging device. You can get one from third-party manufacturers like FLIR, Fluke, and SeeK and pair it with either an Android or iOS device. 

Compared to thermal imagers that cost thousands of dollars, and thermal camera smartphones that are in the $500 range, these mobile-compatible devices are generally more affordable. The FLIR ONE Gen 3, for instance, costs $200, while the SeeK Nano 300 is $300. Another edge of such thermal cameras is their portability. They're pretty compact, so you won't have any trouble lugging them around. 

To use these external thermal cameras with your smartphone, all you have to do is plug them into your charging port, download the camera's app (typically available on the Google Play Store and Apple App Store), and then start scanning. There are also some wireless models that simply connect to your phone via Bluetooth if you need more flexibility. The camera's dedicated apps let you access a bunch of settings, such as color scheme options, temperature unit changes, and even a photo editor.