Make your logo brighter than white

Drop a PNG, JPEG or WebP into the page, choose which colours should glow, and download the result. What comes back is still an ordinary JPEG; for the web it carries an ISO 21496-1 gain map, a small greyscale companion image telling HDR-aware software how far each pixel may be pushed, while the LinkedIn version writes the pixels in BT.2100 PQ with the matching ICC profile. On an HDR display the selected parts read up to 7.5 times brighter than #FFFFFF, which the tool records as 2.9 stops or roughly 1,500 nits.

Light, near white elements on dark backgrounds gain the most, and dark colours cannot really glow because pushing them just reads as washed out neon. The limits are written down on the same page: Chrome, Safari 26, Apple Photos and the LinkedIn apps honour gain maps or PQ profiles, most other platforms strip or normalise them, and there the file simply looks like a normal JPEG.