Use the free Thermal Camera Photo Effect below: upload a photo, adjust the settings, and download your result as a PNG. Your image never leaves your browser — all editing happens on your device, and nothing is uploaded to any server.
What Is a Thermal Look?
Real thermal cameras see heat, not light. They paint cold things dark and hot things bright, usually in a palette that runs from black through red and orange to yellow and white. A person glows against a cold street. A warm engine glows under a cool bonnet. It is a dramatic, instantly readable way to show temperature.
The Thermal Camera Photo Effect on this page recreates that look from a normal photo. It reads the brightness of each pixel and maps it onto the heat palette: dark areas become black and deep red, mid areas become orange and yellow, bright areas become pale yellow and white. The result looks like a thermal camera image, and it is fun for posters, videos and social posts.
An Honest Note First
This is a visual effect, not a measurement. A normal photo records light, not heat. A white shirt in sunlight will look hot in this effect even if it is cold, and a black radiator will look cold even if it is warm. The tool maps brightness to colour, and brightness is only loosely related to temperature.
Never use this effect to judge whether something is safe to touch, whether a person has a fever, or whether equipment is overheating. For any real temperature question, use a real thermal camera or a thermometer. This tool is for art and illustration, not for safety or medical decisions.
How the Effect Works
The tool converts each pixel to a brightness value using the standard weights for red, green and blue, which match how bright a colour looks to the human eye. It optionally blurs that brightness map, which smooths the result into the soft blobs real thermal images have, instead of sharp photographic detail.
Then it maps brightness through a seven-stop heat palette: black, dark red, red-orange, orange, yellow, pale yellow and white. A pixel at half brightness lands between orange and yellow, blended smoothly. The sensitivity control stretches the mapping: higher sensitivity pushes mid-bright pixels toward the hot end, so more of the image glows. Lower sensitivity keeps only the brightest areas hot.
The optional temperature scale adds a vertical bar on the right showing the full palette from cold at the bottom to hot at the top. It is a visual reference, not a calibrated scale: it shows the colour order, not real degrees.
How to Use It
Upload a photo with a bright subject on a darker background: a person against a night street, a lamp in a dark room, a face lit by a window. The effect appears at once. Adjust sensitivity until the subject glows but the background stays cool. Add a blur pass or two if the result looks too photographic and you want the soft thermal feel.
Turn the scale on if you want the classic thermal-camera frame for a poster or thumbnail. Turn it off for a cleaner image. When you like it, press Download PNG.
Tips
High-contrast photos work best. A sunny portrait against shade gives a glowing face and a cool background. A flat, evenly lit photo gives a flat, mostly orange result, because everything has similar brightness. Backlit photos, where the subject is bright and the background is dark, are ideal.
Try the same photo at low and high sensitivity. Low sensitivity gives a mostly dark image with a few hot spots, which looks like a real thermal camera in a cold scene. High sensitivity gives a fiery image, which suits posters and thumbnails.
Privacy
Your photo never leaves your browser. Brightness mapping and rendering happen on your device. Nothing is uploaded, stored or shared.
Frequently Asked Questions
Does this measure real temperature? No. It maps photo brightness to heat colours. It cannot measure temperature.
Why does a white wall look hot? Because it is bright in the photo, and brightness maps to the hot end of the palette.
Can I use it for a video thumbnail? Yes. Thermal-look thumbnails stand out, and the PNG works anywhere images work.