Can GIMP create Ultra HDR or gain-map files?

No. GIMP has no native gain-map HDR export. MakeHDR encodes standards-compliant Ultra HDR (ISO 21496-1) from any JPEG.

Does MakeHDR cost anything?

You can try it with a watermark, then a single payment of $39.99 removes it and unlocks unlimited conversions.

No. It runs in your browser; nothing to install and your photos stay on your device.

GIMP is a free, powerful editor — but exporting true gain-map HDR isn't something it does. MakeHDR is built for exactly that.

GIMP is great for editing on a budget. For real Ultra HDR output that glows on modern screens, MakeHDR is the faster, purpose-built tool.