Hi @gfc - is this happening when you have many images loaded in a scene? What size do these images have?

Here's what I think might be going on:

I recently enabled full resolution previews in the app. This means that all images are now loaded at their maximum device capable resolution (which is still capped at 16 million pixels on iOS thanks to Apple) at startup.
When you have multiple images loaded and their total memory exceeds 384mb (in unpacked RGBA bytes) Safari will crash because no matter how capable your device is, Apple imposes these and other ridiculous restrictions to protect their app store model against web apps.

Here's what I'm working on to mitigate this:

I've already implemented more efficient GPU caching of images so that only the image that's actively being worked on is loaded onto the graphic card. The next step is to also offload all images that are not active to the device storage so that only a single image is held in memory at a time. This will hopefully mitigate these crashes on Apple mobile hardware at the expense of slightly longer delays when switching between images.

Hopefully there's a chance/way and memory to allow the las 3 or something images for a better balance between performance and memory

I continue having problemas with COLOR.IO crashing on iPhone 13, Even 6 images can make it crash (iPhone 13, 12MPix HEIF Safari/now on iOS18)
To alleviate this I try and remember loading no more than 5 images in total which in my case is limiting and erase previous images before loading more but I understand what you explained about the change you made loading the images at full resolution now. In practice I preferred the way the app worked previously because I never had a problema/crash with the number of images loaded so maybe you could Add a TOGGLE/Option for choosing between using Full Res or how it was before so one can pick between more images or better quality (full res)

Additionally this also happens on my MAC (MBP M1 Pro 14" 16RAM Safari 18.0.1 (19619.1.26.111.11, 19619)) many times losing work in progress, before I never experienced a crash even though I had loads of images, I still can manage lots more images than on iPhone 13 but before this had never happened with same quantity of images from a SONY A7III (24 Mpix TIFF/JPG).

Another common occurrence for the app is to simply upon opening require me to relog in even though I never log out of the session losing all previous work done (And the app/system says I'm still logged in and recognizes my user-avatar) and this can happen 3 days from when I have loaded images and used program everyday.

Thanx