NEF to WEBP lossless

[DO3EET]

Hi all
I'm new to XnConvert, but I'm currently in need of an tool like this.
I was in Japan with friends a few weeks ago and we used SyncThing to exchange pictures. Most of us took photos in JPG or RAW+JPG, except for one. As a Linux user and the only computer engineer, I had the idea of converting the NEF images into a modern lossless format. My first choice was webp, as I also use it for my website. I was very surprised when I realised that the NEF files were smaller than the WEBP results after the conversion. Both are of course formats that can handle compression, but WEBP is far more up-to-date from my point of view, which is why I suspect a mistake on my part...

Have you had similar experiences? How would you save the images without loss, in a format that modern devices can display?

[Kadet]

The modern format that can save lossy/lossless HDR 12-14 bits NEF is Jpeg XL (jxl). It's new, now stable format, which replace Jpg, png, webp... But, because it's new format is not included to all programs/systems for now.

Only AVIF can fight with JXL but only on websites. And only in lossless option. BTW I recommended to You use lossless Avif on Your site.