Reduce the size of .HDR files

Hi folks,
kinda new here

Soo…i’ve been playing around with three.js path tracer renderer and image based lighting.

Currently the .HDR files i’m lighting my scenes with are over 5mb big for a 2048px x 1024px environment image. Which is quite large for the webbased tool we’re developing. I’ve been looking at ways but I could not find anything

Would anybody know ways of making the .hdr file size smaller? To make the scene more smaller and faster loading.

Or even if .TIFF would be suitable for IBL since they are also 32bit and have more compression options in the tools I use.

.hdr, compression, reduce size,


Have you already give HDRJPG a try? It’s a relatively new thing in three.js (available since r159) but you can read more about it here: Adopt (or simply promote) a new true HDR file format leveraging JPEG/WEBP compression. Potentially alleviates HDR and EXR file size issues · Issue #27171 · mrdoob/three.js · GitHub

This new format helps with reducing file sizes which are indeed a problem when using classic formats like HDR or EXR. It also supports Ultra HDR.

There is a new example that demonstrates the usage of the external HDRJPGLoader module. For creating compatible HDR images I suggest you read the instructions of the respective repository:


I hadn’t heard of it before. My hdr’s used to be like 100mb for lighting scenes. Now that i’ve turned webbased I have to find new way’s and keeping it optimised. I’ll have to look into it
It’s quite impressive… 4096x2048 = 1.8mb